View MC33293AT_38952.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Order this document by MC33293A/D
MC33293A
Advance Information Quad Low Side Switch
The MC33293A is a single monolithic integrated circuit designed for quad low side switching applications. This device was initially conceived as a quad injector driver for use in the harsh automotive environment but is well suited for many other applications. The MC33293A incorporates SMARTMOSTM technology having CMOS logic, bipolar and CMOS analog circuitry and DMOS power MOSFETs. All of the device inputs are CMOS compatible. The four output devices are N-channel power MOSFETs. A Fault detect output is provided to flag the existence of open loads (outputs ON or OFF) or shorted loads. If a short circuit is detected, the fault detect circuitry turns off the shorted output, but allows the others to function normally. An overvoltage (VPWR) condition will turn off all outputs for the overvoltage duration. Each output functions independently and has a drain-to-gate diode clamp for inductive flyback voltage protection. A Single/Dual select pin is incorporated to allow either individual output control or control of a pair of outputs from one input. The MC33293A is parametrically specified over - 40C TA 125C ambient temperature and a 9.0 V VPWR 14.5 V supply. * Designed to Operate with Supply Voltages of 5.5 V to 30 V
QUAD LOW SIDE SWITCH
(RDS(on) = 0.25 Max per Output)
SEMICONDUCTOR TECHNICAL DATA
1
* * * * * * * * * *
CMOS Compatible Inputs with Active Pull-Downs Maximum 5.0 mA Quiescent Current RDS(on) of 0.25 Maximum at 25C, with VPWR 9.0 V Each Output Clamped to 65 V for Driving Inductive Loads Each Output Current Limited at 3.0 A to handle Incandescent Lamp Loads Active Low Output Fault Status with Interrogation Capability Open Load Detection (Output ON or OFF) Capable of Withstanding Reverse Battery Overvoltage Shutdown Short Circuit Detection and Shutdown with Automatic Retry
1
T SUFFIX PLASTIC PACKAGE CASE 821D
TV SUFFIX PLASTIC PACKAGE CASE 821C
PIN CONNECTIONS
Pin 1. Output 2 2. Output 1 3. Input 1 4. Input 2 5. Input 1 & 2 6. Single/Dual 7. VPWR 8. Gnd 9. N/C 10.Fault 11. Input 3 & 4 12.Input 4 13.Input 3 14.Output 3 15.Output 4
ORDERING INFORMATION
Device MC33293AT MC33293ATV TJ = -40 to +150C 15 Pin SIP Operating Temperature Range Package
This document contains information on a new product. Specifications and information herein are subject to change without notice. DEVICE DATA MOTOROLA ANALOG IC
(c) Motorola, Inc. 1996
Rev 0
1
MC33293A
Simplified Block Diagram
7 3 Input 1 4 Input 2 13 Input 3 12 Input 4 5 Input 1 & 2 Single/Dual 6 Select 11 Input 3 & 4 10 Fault Fault Encoder From Detectors 2,3,4 Open Load Detect Short Circuit Detect To Gates 2,3,4 15 Output 4 Gate Control 2 1 Output 2 14 Output 3 Output 1 Overvoltage Shutdown Bias Circuit Bias +VPWR
Ilimit RS 8 Ground
MAXIMUM RATINGS
Rating VCC Steady-State Transient Conditions Input Pin Voltage ESD Capability Human Body Model (R = 1.5 k, C = 200 pf) Lead Current (per Output) Single Pulse Clamp Energy @ 25C, 1.5 A Storage Temperature Operating Temperature Lead Temperature (Wave Solder, 10 s) Power Dissipation @ TA = 105C Power Dissipation @ TA = 125C Derate for every C above 25C Thermal Resistance Junction-to-Ambient Thermal Resistance Junction-to-Case. Any one O/P Symbol VPWR VPWR(pk) Vin VESD 2000 IOut Eclamp Tstg TJ Tsolder PD Internally Limited 100 - 55 to +150 - 40 to +150 260 11.25 6.25 0.25 35 4.0 A mJ C C C W W/C C/W C/W Value -13 to 30 -13 to 60 - 0.5 to 7.5 V V Unit V
RJA RJC
2
MOTOROLA ANALOG IC DEVICE DATA
MC33293A
STATIC ELECTRICAL CHARACTERISTICS (9.0 V VPWR 14.5 V and - 40C TC +125C, unless otherwise
noted. Typical values are at 25C, unless otherwise noted.) Characteristic INPUT Turn ON Threshold Operating Voltage Range Quiescent Power Supply Current (All Inputs off) Overvoltage Shutdown Range Overvoltage Reset Hysteresis Input Voltage High (IDS = 1.0 A) Low (IDS = 80 A) Input High Hysteresis (IDS = 1.0 A) Input Current High (VIH = 3.0 V) Low (VIL = 0.8 V) OUTPUT Static Drain-Source On-Resistance (IDS = 1.0 A, VPWR = 13 V, TC = - 40C to + 25C) (IDS = 1.0 A, VPWR = 13 V, TC = +125C) (IDS = 0.7 A, VPWR = 8.0 V, TC = + 25C) (IDS = 0.4 A, VPWR = 5.5 V, TC = + 25C) Drain-Source Clamp Voltage (IDS = 20 mA, Vin = 0 V, tclamp = 100 s) Zero Input Voltage Drain Current (VDS = 25 V, VPWR = 14.5 V) (VDS = 58 V, VPWR = 14.5 V) Source Drain Diode Forward Voltage (ISD = 1.0 A) RDS(on) -- -- -- -- BVDSS 55 IDS(off) 10 -- VSD -- 23 0.06 0.62 80 2.0 1.4 64 80 A mA V 0.18 0.28 0.20 0.22 0.25 0.50 0.40 0.50 V Von(th) VPWR IPWR VPWR(ov) VPWR(hys) VIH VIL VIH(hys) IIH IIL -- 5.5 -- 30 2.0 3.0 -- 0.4 -- -- 3.4 -- 2.2 35 5.0 2.3 1.6 0.7 11 11 5.5 30 5.0 38 7.0 -- 0.8 -- 50 50 V A V V mA V V V Symbol Min Typ Max Unit
MOTOROLA ANALOG IC DEVICE DATA
3
MC33293A
STATIC ELECTRICAL CHARACTERISTICS (continued) (9.0 V VPWR 14.5 V and - 40C TC +125C, unless otherwise
noted. Typical values are at 25C, unless otherwise noted.) Characteristic FAULT STATUS OUTPUTT Fault Status Pin Low Voltage (VPWR = 14.5 V, Istl = 1.0 mA, open-load on Output 1, 2, 3 or 4. All inputs = 0 V) High Voltage, (VPWR = 14.5 V, Isth = - 30 A, Note 1) FAULT DETECTION Output Limiting Current (VPWR = 13 V) Over-Current Detect Voltage Threshold and Output-Off Open-Load Detect Threshold Voltage output-on open-load Detect Current (VPWR = 13 V, Vin = 5.0 V, TC = - 40C) (VPWR = 13 V, Vin = 5.0 V, TC = + 25C) (VPWR = 13 V, Vin = 5.0 V, TC = +125C) IDS(limit) VOC(limit) VOoff(th) IOon(th) 20 20 20 80 75 65 190 130 100 3.0 2.4 2.4 4.0 3.7 3.7 6.0 5.0 5.0 A V mA V Vstl Vsth -- 3.0 0.1 4.7 0.4 5.5 Symbol Min Typ Max Unit
DYNAMIC ELECTRIC CHARACTERISTICS
Characteristic OUTPUT TIMING Output Driver Rise Time (VCC = 13 V, RL = 13 , tr = Output Voltage change from 90% to 10%, see Figure 2) Output Driver Fall Time (VCC = 13 V, RL = 13 , tf = Output Voltage change from 10% to 90%, see Figure 2) Output Delay Time (VCC = 13 V, RL = 13 , ton(dly) = Vin at 3.0 V to VO at 90%, see Figure 2) toff(dly) = Vin at 1.0 V to VO at 10%, see Figure 2) FAULT TIMING Over-Current Sense Time (See Figure 5 or 6) (Vin = 5.0 V, RL = 0.05 , VPWR = 14.5 V, over-current duty cycle 10% toc = time that VStatus is > 1.0 V) Over-Current Refresh Time (See Figures 5 or 6) (Vin = 5.0 V, RL = 0.05 , VPWR = 14.5 V, over-current duty cycle 10% tref = time that VStatus is < 1.0 V) Output Open-Load Fault Status Delay Time (VPWR = 13 V, Vin = 5.0 V, open-load on Output, tos(on) = time from Vin = 3.0 V to VStatus = 1.0 V, see Figure 3) (VPWR = 13 V, Vin = 0 V, open-load on Output, tos(off) = time from Vin = 2.5 V to VStatus = 1.0 V, see Figure 4) Fault Status Reset Delay Time (VPWR = 13 V, Vin = 0 V, see Figure 4)
NOTE: 1. Negative current signifies current flowing out of device.
Symbol
Min
Typ
Max
Unit s s s
tr tf
-- --
2.3 1.5
10 10
ton(dly) toff(dly) toc
-- --
3.2 5.9
10 15 s
10
55
250
tref 1.5 3.6 7.0
ms
ms tos(on) 1.0 tos(off) 1.0 ts(reset) -- 2.0 10 19 40 s 2.2 4.0 s
t
4
MOTOROLA ANALOG IC DEVICE DATA
MC33293A
Figure 1. Fuel Injector Application Block Diagram
MC68HC11A1
VLoad (Battery)
+14V
7 OC 2 Input 1 3 Input 2 OC 3 Input 3 OC 4 13 Input 4 OC 5 12 Input 1 & 2 PD 0 5 PD 1 Select 6 Input 3 & 4 PD 2 11 11A x 7 IRQ Open Load Detect Short Circuit Detect G2 Short Circuit Detect Injector 2 (14, 10mH) (1) 23A 1 Open Load Detect ILimit RS 4 Gate Control G2 G3 G4 Overvoltage Shutdown Bias Circuit
Bias 23A 2
Injector 1 (14, 10mH) (1)
ILimit RS
100A Fault 10 Fault Encoder
23A 14
Injector 3 (14, 10mH) (1)
Open Load Detect Short Circuit Detect
G3
ILimit RS
23A 15 Open Load Detect Short Circuit Detect
Injector 4 (14, 10mH) (1)
G4
ILimit RS
NOTE: 1. The MC33293A is also designed to drive the 194 type incandescent instrument lamp.
8
MOTOROLA ANALOG IC DEVICE DATA
5
MC33293A
Figure 2. Switching Speed Test Circuit and Response Times
13V Vload 13 VPWR 10V Input Input 50 Vin 3 4 13 12 10 50 0V 100s Input 1 Input 2 Input 3 Input 4 Status 7 Out 1 Out 2 Out 3 Out 4 2 1 14 15 VO
13V
Test Circuit
MC33293A
5 Input 1 & 2 11 Input 3 & 4 6 Select Gnd 8
2% Duty Cycle Gnd
Response Times
5.0V
Vin
3.0V
1.0V 0V
ton ton(dly) tr toff(dly)
toff tf
13V 90% VO
10% 0V
6
MOTOROLA ANALOG IC DEVICE DATA
MC33293A
Figure 3. Fault Status Operation with an Output-On, Open-Load Fault
5.0V Vin 0V 3.0V 1.0V
5.0V VStatus 1.0V 0V tos(on) * Open Load Fault Reported IO 0A Open Load Fault Ends
* If the open occurs after the output has been on, the delay time is much less than tos(on). NOTE: Rise and fall times are exaggerated for emphasis.
1.0A (Normal Load) IOon(th)
Figure 4. Fault Status Operation with an Output-Off, Open-Load Fault
5.0V Vin 0V ts(reset) 5.0V VStatus (All Outputs Off) 0V tos(off) * Open Load Fault Reported VO 0V
* If the open occurs after the output has been off, the delay time is much less than tos(off). NOTE: Rise and fall times are exaggerated for emphasis.
2.5V
3.0V 1.0V
Vload VOoff(th)
Open Load Fault Ends
MOTOROLA ANALOG IC DEVICE DATA
7
MC33293A
Figure 5. Fault Status Operation with Turn On into an Over-Current Load
5.0V Vin 0V 3.0V
5.0V VFault Status 1.0V 0V toc tref IDS(limit) IO Output Shutdown Over-Current condition at Turn On Over-Current condition Ends Refresh (Turn on and test load) 1.0A (Normal Load)
0A
NOTE: Rise and fall times are exaggerated for emphasis.
Figure 6. Fault Status Operation with Over-Current Load after Turn On
5.0V Vin 0V 3.0V
5.0V VFault Status 0V 1.0V tref 1.0V toc IDS(limit) IO 1.0A 0A Over-Current condition occurs Output Shutdown Output Shutdown Refresh (Turn on and test load)
NOTE: Rise and fall times are exaggerated for emphasis.
8
MOTOROLA ANALOG IC DEVICE DATA
MC33293A
Figure 7. Turn On Threshold Voltage versus Temperature
6.0 5.0 4.0 3.0 2.0 1.0 0 - 55 VPWR = Von(th) VDS = 14.5 V Vin = 5.0 V RDS(on) , OUTPUT ON RESISTANCE ( ) 0.30 0.28 0.26 0.24 0.22 0.20 0.18 0.16 0.14 0.12 0.10 - 55 ID = 1.0 A VPWR = 13 V Vin = 5.0 V
Von(th), TURN ON THRESHOLD VOLTAGE (V)
Figure 8. Output On Resistance versus Temperature
- 25
0
25
50
75
100
125
- 25
0
25
50
75
100
125
TA, AMBIENT TEMPERATURE (C)
TA, AMBIENT TEMPERATURE (C)
80 76 72 68 64 60 - 55 VDS = BVDSS VPWR = 14.5 V Vin = Open
I DS(off), ZERO INPUT VOLTAGE DRAIN CURRENT ( A)
BVDSS, DRAIN SOURCE CLAMP VOLTAGE (V)
Figure 9. Drain Source Clamp Voltage versus Temperature
Figure 10. Zero Input Voltage Drain Current versus Temperature
80 70 60 50 40 30 20 10 0 - 55 - 25 0 25 50 75 100 125 VDS = 25 V VPWR = 14.5 V Vin = 0 V
- 25
0
25
50
75
100
125
TA, AMBIENT TEMPERATURE (C)
TA, AMBIENT TEMPERATURE (C)
IDS(Limit), DRAIN SOURCE CURRENT LIMIT (A)
VOoff(th) , OPEN-LOAD DETECT THRESHOLD (V)
Figure 11. Current Limit versus Temperature
6.0 5.5 5.0 4.5 4.0 3.5 3.0 - 55 VDS = 2.8 V VPWR = 13 V Vin = 5.0 V
Figure 12. Open-Load Threshold versus Temperature
5.0 4.5 4.0 3.5 3.0 2.5 - 55 VDS = 13 V VPWR = 13 V Vin = 0 V
- 25
0
25
50
75
100
125
- 25
0
25
50
75
100
125
TA, AMBIENT TEMPERATURE (C)
TA, AMBIENT TEMPERATURE (C)
MOTOROLA ANALOG IC DEVICE DATA
9
MC33293A
PIN DESCRIPTION
Pin 1 2 3 4 5 Function
Output 2
Description This is one of four open drain power MOSFET output connections. The load is connected from this pin to the positive voltage supply. This is one of four open drain power MOSFET output connections. The load is connected from this pin to the positive voltage supply. This input controls the turn ON and turn OFF of Output 1 when the Single/Dual pin is at a logic low level. It is a CMOS input with an internal active pull-down employed for noise immunity. This input controls the turn ON and turn OFF of Output 2 when the Single/Dual pin is at a logic low level. It is a CMOS input with an internal active pull-down employed for noise immunity. This input controls the turn ON and turn OFF of Output 1 and Output 2 when the Single/Dual select pin is at a logic high level. It is a CMOS input with an internal active pull-down employed for noise immunity. This input selects between the single (one input controls one output) mode and the dual (one input controls two outputs) mode of operation. The power (voltage and current) to operate the IC is supplied through this pin. The MC33293A is designed to operate over a voltage range of 5.5 V to 30 V. IC ground reference pin. No connection. One of three fault conditions, Output-On Open-Load, Output-Off Open-Load or Over-Current are reported at this output. A logic low state signals the existence of a fault condition. This output has an internal active pull-up and does not require an external pull-up resistor. This input controls the turn ON and turn OFF of Output 3 and Output 4 when the Single/Dual select pin is at a logic high level. It is a CMOS input with an internal active pull-down employed for noise immunity. This input controls the turn ON and turn OFF of Output 4 when the Single/Dual pin is at a logic low level. It is a CMOS input with an internal active pull-down employed for noise immunity. This input controls the turn ON and turn OFF of Output 3 when the Single/Dual pin is at a logic low level. It is a CMOS input with an internal active pull-down employed for noise immunity. This is one of four open-drain power MOSFET output connections. The load is connected from this pin to the positive voltage supply. This is one of four open-drain power MOSFET output connections. The load is connected from this pin to the positive voltage supply.
Output 1
Input 1
Input 2
Input 1 & 2
6 7 8 9 10
Single/Dual Select VPWR Ground N/C Fault
11
Input 3 & 4
12 13 14 15
Input 4
Input 3
Output 3
Output 4
CIRCUIT DESCRIPTION
Introduction The MC33293A is a four output low side switch originally intended for use in automotive applications as a fuel injection driver. This circuit can be used in a variety of applications. It is parametrically specified over a battery voltage range of 9.0 V to 14.5 V, but is designed to operate over a considerably wider range of 5.5 V to 30 V. The design incorporates the use of logic level MOSFETs as output devices which are fully enhanced at a gate voltage of 5.0 V, eliminating the need for internal charge pumps. Each output is identically sized and is independent in operation. The efficiency of each output device is such that with as little as 9.0 V of VPWR applied, the RDS(on) is 0.18 typically, at room temperature and increases to only 0.22 as VPWR decreases to 5.5 V. All inputs of the MC33293A are CMOS and have individual 11 A internal active pull-downs. This eliminates the need for external pull-down resistors to prevent false switching due to noise on the input control lines. This also ensures that at 10 power-up, no load is turned on before a logic high appears on an input pin. Fault reporting is through the use of an open-drain MOSFET having a 100 A internal active pull-up. All inputs incorporate true logic (or positive logic). This means that whenever an input is in a logic low state (< 0.8 V) the corresponding output will be in an OFF state. Conversely, whenever an input is in a logic high state (> 3.0 V), the corresponding output will be in an ON state. Single/Dual Select The Single/Dual Select pin can be used to switch between completely independent control and control of the outputs in pairs. Whenever the Single/Dual Select pin is in a logic low state, Inputs 1, 2, 3 and 4 control Outputs 1, 2, 3 and 4, respectively. In this mode, only Inputs 1, 2, 3 and 4 can exercise individual control over their respective output. Hence the term "single select" mode of operation. Input 1 & 2 (Pin 5) and Input 3 & 4 (Pin 11) have no control whenever the Single/Dual Select pin is in a logic low state. MOTOROLA ANALOG IC DEVICE DATA
MC33293A
When the Single/Dual Select pin is held at a logic high state, Control Inputs 1, 2, 3 and 4 are turned OFF and can not exercise any control over the outputs. In this mode, input control transfers from a single to a dual mode of operation, wherein only Input 1 & 2 and Input 3 & 4 have control of Output 1 plus Output 2, and Output 3 plus Output 4, respectively. Hence the term "Dual Select" mode of operation. Paralleling Outputs Paralleling outputs may be desirable in the event the application requires a lower RDS(on) or higher current switching capability than a single output. The MC33293A can be operated with all outputs (and therefore all inputs) tied together but modified operation is to be expected. With all inputs tied together and depending on the dual or single select mode used, the paralleled input control current will either be twice (with the dual mode selected) or four times (with the single mode selected) that of any single input. Other expected differences are: RDS(on) will decrease by a factor of four while the Output-On Open-Load Detect current and the Output Limiting current will increase by a factor of four. There will be no change in the Over-Voltage Shutdown Range or the Output-Off Output-On Open-Load Detect Threshold Voltage Range. As always, system level thermal design and verification are important when outputs are paralleled.
FAULT LOGIC OPERATION
General The Fault Status output (Pin 10) on the MC33293A reports any one of three possible faults from any one of the four outputs. The three possible faults are output-on open-load Fault, output-off open-load Fault and over-current Fault. All faults from any of the four outputs are OR'd together and reported by the single Fault Status output-on Pin 10 (Figure 13).
Figure 13. MC33293A Fault Logic Diagram
Output-Off open-load Fault Report 1 Output-Off open-load Fault Report 2 Output-Off open-load Fault Report 3 Output-Off open-load Fault Report 4 100A Fault Input 1 Input 2 Input 3 Input 4 Single/Dual Select Input 1 & 2 Input 3 & 4
output-on open-load Fault Report 1 output-on open-load Fault Report 2 output-on open-load Fault Report 3 output-on open-load Fault Report 4
output-on Over-Current Fault Report 1 output-on Over-Current Fault Report 2 output-on Over-Current Fault Report 3 output-on Over-Current Fault Report 4
MOTOROLA ANALOG IC DEVICE DATA
11
MC33293A
Output-On open-load Fault The MC33293A always checks for an open-load on the outputs whether the outputs are ON or OFF. An output-on open-load Fault is detected if an open-load exists when the output is ON (corresponding input at a logic high state). The output-on open-load Fault detection occurs when the load current is less than the minimum Output-On Open-Load Detect current (IOon(th)), specified in this data sheet. The value of IOon(th) is, typically, 75 mA at room temperature. See Figure 3. The minimum load resistance value that the MC33293A will interpret as an output-on open-load (Ropen(on)) is a function of; the Output-On Open-Load Detect current (IOon(th)); the load supply voltage (Vload); and the resistance of the output (RDS(on)), as shown below. Ropen(on) = [Vload / IOon(th)] - (1) RDS(on) Vload / IOon(th) Using Equation 1 for the steady state case, when: Vload = 14 V RDS(on) = 0.3 IOon(th) = 75 mA an output-on open-load Fault will be detected and reported whenever Rload 187 . Each output has an output-on open-load fault detect circuit that performs real time load current monitoring. Load current is monitored immediately after any output is turned ON. Since it takes a finite amount of time for load current to begin, the MC33293A detects an output-on open-load Fault from the time the output is turned ON until the load current exceeds the Output-On Open-Load Detect current (IOon(th)). It is important to note that a fault will not be reported at the Fault Status output during this short period of time. This is due to the built-in output-on open-load Fault Status Delay Time (toson), see Figure 3. This delay time is incorporated in the MC33293A to mask the reporting of a false output-on open-load Fault at the Fault Status output. The delay is typically 2.2 ms. The purpose for the tos(on) delay is to prevent false fault reporting, especially when driving inductive loads. The load inductance causes a current lag when the load is turned ON. The normal current lag of an inductive load could be misinterpreted as an open-load if it weren't for the built-in delay. This delay or masking is accomplished internally with a single timer which resets every time any input switches from a low-to-high logic state. An output-on open-load Fault will be reported by the Fault Status output as a result of turning ON an output having an open-load Fault and the most recent tos(on) is allowed to lapse after switching ON any input. The time it takes the load current to reach IOon(th) is a function of the load resistance (Rload); load inductance (Lload); output on resistance (RDS(on)); load supply voltage (Vload); and the turn-on time (ton) as shown below. The value of ton is comprised of the low-to-high Vin propagation delay time (ton(dly)), and the output voltage rise time (tr). See Figure 2. ton(false fault) = - ln [(IOon(th)- Iload)/ (2) (- Iload)] + ton where: = Lload / Rload = time constant Iload = Vload / [Rload + RDS(on)] ton = ton(dly) + tr (3) (4) (5) Using Equation 2 for the transient case, when: Vload = 14 V RDS(on) = 0.3 Lload = 10 mH Rload = 14 IOon(th) = 75 mA an output-on open-load Fault will be detected, but not reported after initial turn ON for a duration of 57 s + ton. Output-Off open-load Fault The MC33293A checks for open-loads on the outputs regardless of an output being on or off. An output-off open-load Fault is detected if an open-load exists when the output is turned OFF (corresponding input at a logic low state). When any one of the four outputs are turned OFF, an independent internal current source tied to each output tries to pull a small amount of zero input voltage drain current (IDS(off), typically 23 A), through the load. If, while this zero input voltage drain current is being pulled through the load, the output voltage is less than the output-off open-load Detect Threshold Voltage (VOoff(th), typically 3.7 V), an output-off open-load Fault will be detected. The zero input voltage drain current could be provided by a large external resistor connected from the output to ground. However, if an external resistor were used to provide this zero input voltage drain current, only "opens" resulting from open-loads or output to ground shorts could be detected. The external resistor could not guarantee detection of an open resulting from an output wire bond failure internal to the MC33293A. Because the current source is provided internally, open loads, output to ground shorts, and loss of output wire bonds will all be detected. The value of load resistance that will be detected as an output-off open-load (Ropen(off)), is a function of the zero input voltage drain current (IDS(off)); the load supply voltage (Vload); and the output-off open-load Detect Threshold Voltage (VOoff(th)), as shown next by: (6) [Vload - VOoff(th)] Ropen(off) = IDS(off) Using Equation 6 for the steady state case, when: Vload = 14 V IDS(off) = 23 A VOoff(th) = 3.7 V an output-off open-load Fault will be detected and reported whenever RL 448 k. Each output has an output-off open-load fault detect circuit that performs real time output voltage monitoring. Output voltage is monitored immediately after any output is turned off. A finite amount of time is required for output voltage to rise. The MC33293A detects an output-off open-load Fault from when an output is turned off until the output voltage exceeds the output-off open-load Detect Threshold Voltage (VOoff(th)). It is important to note a fault will not be reported at the Fault Status output during this rise time. This is due to the built-in output-off open-load Fault Status Delay Time, tos(off), see Figure 4. This delay time is incorporated in the MC33293A to delay the reporting of an output-off open-load Fault at the Fault Status Output. The delay is typically 19 s.
12
MOTOROLA ANALOG IC DEVICE DATA
MC33293A
The purpose for the tos(off) delay is to prevent false fault reporting experienced with capacitance type loads. The load capacitance causes the rise in output voltage to lag even after the load has been turned OFF. The normal voltage lag caused by load capacitance could be misinterpreted as an open-load if it weren't for the built-in delay. This delay, or masking, is accomplished with four separate timers that reset independent of each other when the corresponding input is switched from a high to a low logic state. Internal logic prevents an output-off open-load Fault from being reported at the Fault pin when any input is high. An output-off open-load Fault will be reported at the Fault Status pin after an open load occurs, all inputs not corresponding to the faulted output are low and a time in excess of tos(off) is exceeded after switching OFF the input corresponding to the faulted output. An important note that bears repeating is that an output-off open-load Fault will not be reported at the Fault Status pin unless all input pins are at a logic low state (Figure 13). This is a Fault Status interrogation feature. It helps in distinguishing between an output-on open-load Fault and an output-on over-current Fault. (Fault Status interrogation is explained in greater detail in a later section). The time the output voltage takes to reach VOoff(th) after being turned OFF is toff false fault. It is a function of the load resistance (Rload); load inductance (Lload); load current (Iload); output-on resistance (RDS(on)), output capacitance (CO); load supply voltage (Vload); and the turn OFF time (toff). The value of toff is comprised of the Vin high-to-low propagation delay time (toff(dly)), and the output voltage fall time (tf). For the case when: 1/2 Lload (Iload)2 >> 1/2 CO (VOoff(th))2 (7) toff false fault = [(CO V) / Iload] + toff where: Iload = Vload / [Rload + RDS(on)] (8) (9) load current exceeds the internal current limit value (typically 4.0 A). An over-current condition activates the current limit circuit. This circuit then sends an analog signal to the gate control circuit, lowering the voltage on the output transistor's gate. Lowering the gate voltage forces the output transistor to transition from the resistive (fully enhanced) mode of operation to the current limit (between fully enhanced and fully OFF) mode. The actual detection of an over-current condition does not occur at the initial onset of current limit. The onset of current limit causes the voltage on the affected output to increase. The actual Over-Current detection occurs when the output voltage increases and exceeds the over-current Detect Voltage Threshold (VOC(limit), typically 3.7 V), while the corresponding input signal is in a logic high state. After detection, the reporting of an over-current Fault at the Fault Status output is delayed by a time equal to the over-current Sense Time (toc), see Figures 5 and 6. This delay time is typically 55 s. If the over-current condition no longer exists after the over-current Sense Time has passed, then no fault is reported. The purpose of the Fault reporting delay is to blank any false faults that might be reported due to high inrush current loads such as incandescent lamps. If the over-current condition still exists after the delay time has passed, then a fault will be reported at the Fault Status output and the affected output is turned OFF. The Over-Current Sense Time is accomplished internally with four separate timers that reset and start independent of each other whenever a corresponding output is turned ON, either due to the corresponding input turning ON or the completion of the over-current Refresh Time (tref) explained in the next paragraph, (see Figures 5 and 6). An over-current Fault will be reported at the Fault Status output when an over-current condition is detected and a lapse time in excess of toc is exceeded after turning ON the affected output. At the same time the over-current Fault is reported, a single internal over-current refresh timer resets, causing any over-current outputs to be turned OFF for a duration of tref, typically 3.6 ms. After a time tref, the faulted output(s) will be turned ON again to check if the over-current condition still exists. If the over-current condition still exists, the output(s) will be turned OFF again after a time toc. This periodic retry continues turning ON and OFF over-current loads at a duty cycle of toc /(toc + tref) with a period of toc + tref until either the input is turned OFF or the over-current condition is removed. Any subsequent over-current conditions will reset and restart the tref timer. Detection of an over-current condition coincides with, but does not occur until after the onset of current limit. This allows a specific but small current limit range to go undetected. The factors that determine the value of load resistance causing an over-current condition to be detected are: the Output-Load Current Limit [IDS(limit)]; load voltage (Vload); and the Over-Current Detect Threshold Voltage [VOC(limit)] as shown below: [V - VOC(limit)] (12) Rload(detect) = load IDS(limit)
V = VOoff(th) - [Iload RDS(on)] (10) (11) toff = toff(dly) + tf Using Equation 7 for the transient case, when: Vload = 14 V RDS(on) = 0.3 Lload = 10 mH Rload = 14 CO = 0.001 F VOoff(th) = 3.7 V an Output-Off open-load Fault will be detected but not reported after initial turn OFF for a duration of 3.5 ns + toff. From Equation 7, the energy stored in the load inductor will be 4.8 mJ. This is much greater than the 68 nJ needed to charge the output capacitance. This allows the use of Equation 8 in determining the false output-off open-load Fault duration following turn OFF because it assures that the output capacitance will be charged by the energy stored in the load inductance. Over-Current Fault An over-current (short circuit or current limit) Fault is the detection and reporting of any output over-current condition. An over-current condition is defined as a condition where
MOTOROLA ANALOG IC DEVICE DATA
13
MC33293A
The factors that determine the value of load resistance that will cause the onset of current limit are: IDS(limit), Vload, and RDS(on), as shown below. Rload(limit) = [Vload / IDS(limit)] - RDS(on) (13) For the case when: Vload = 14 V VOC(limit) = 3.7 V RDS(on) = 0.3 IDS(limit) = 4.0 A an over-current condition will be detected for any load resistance such that Rload 2.6 . An undetected current limit condition will occur any time 2.6 Rload 3.2 . Notice that the undetected current limit range is quite small. Fault Interrogation Even though the MC33293A incorporates a single Fault Status Output pin for reporting three different fault conditions, a real time interrogation routine can be used to determine which one of the three Fault conditions is being reported and which single output is affected. An important point to note about Fault interrogation is that only one fault on a single output can be interpreted. In other woRDS, if more than one over-current or open-load Fault exists among the four outputs, it is not possible to distinguish which outputs have a fault and which do not. It is very unlikely, however, that more than one output will be faulted at the same time. When a Fault is reported, the first step is to determine if it is an over-current or open-load Fault (Rload 447 k, typical). This is done by taking all the inputs (single or dual) to a logic low state. If the Fault Status resets (changes to a logic high state) after the Fault Status Reset Delay Time (ts(reset), see Figure 4) has lapsed, then an over-current Fault is being reported. If the Fault Status does not reset (remains at a logic low state) after ts(reset) has lapsed, then an open-load Fault (Rload 447 k, typical) is being reported. This type of interrogation is possible because an output-off open-load Fault can only be reported when all the inputs are in a logic low state. For an over-current Fault, the next step is to determine which single output is affected. After all inputs are turned OFF and the fault status resets, each input is then turned ON then OFF sequentially. A Fault will again be reported when the input to the corresponding Over-Current output is turned ON and tos(on) has lapsed. If the dual input mode is being used, an over-current Fault can only be interrogated down to the two outputs being driven together. For an open-load Fault (Rload 447 k, typical) interrogation, all inputs are turned OFF and the fault status remains set. Each input is then turned ON and OFF sequentially. The Fault status will remain set when the input to the corresponding faulted output is turned ON and tos(on) has lapsed. If the dual input mode is used, an open-load Fault can only be interrogated down to the two outputs driven together. From the example following Equation 1, the typical value of Ropen(on) is 187 . From the example following Equation 6, the typical value of Ropen(off) is 447 k. Therefore, if the load resistance is between 187 and 447 k typically, an output-on open-load Fault will be reported at the Fault Status output but an output-off open-load Fault will not. This condition is referred to as a soft open fault. If a soft open fault exists, it is reported at the Fault Status output the same as an over-current Fault except for the reporting delay time. A soft open fault has a reporting delay time of 2.2 ms typically, and an over-current Fault has a reporting delay time of only 55 s typically, after the input to the faulted output is turned ON.
14
MOTOROLA ANALOG IC DEVICE DATA
MC33293A
Figure 14. Truth Table
Inputs Conditions of Outputs Non-Faulted Operation 1 L L L L L L L L H H H H H H H H X X X X L H L H X X X X L H L H X X X X 2 L L L L H H H H L L L L H H H H X X X X L L H H X X X X L L H H X X X X 3 L L H H L L H H L L H H L L H H X X X X L L H H X X X X L L H H X X X X 4 L H L H L H L H L H L H L H L H X X X X L L H H X X X X L L H H X X X X S/D L L L L L L L L L L L L L L L L H H H H L L L L H H H H L L L L H H H H 1&2 X X X X X X X X X X X X X X X X L H L H X X X X L H L H X X X X L H L H 3&4 X X X X X X X X X X X X X X X X L L H H X X X X L L H H X X X X L L H H 1 H H H H H H H H L L L L L L L L H L H L L L L L L L L L H H H H H H H H 2 H H H H L L L L H H H H L L L L H L H L H H L L H L H L H H L L H L H L Outputs 3 H H L L H H L L H H L L H H L L H H L L H H L L H H L L H H L L H H L L 4 H L H L H L H L H L H L H L H L H H L L H H L L H H L L H H L L H H L L Fault H H H H H H H H H H H H H H H H H H H H L L H* L L L H* L H L H L H L H L
open-load Fault On Output 1
Over-Current Fault On Output 1
*NOTE: All inputs must be a logic low state for an Output-Off open-load Fault to be reported.
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. "Typical" parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer.
MOTOROLA ANALOG IC DEVICE DATA
15
MC33293A
OUTLINE DIMENSIONS
T SUFFIX PLASTIC PACKAGE CASE 821D-03 ISSUE C Q -L- B -P- U A R K
PIN 1 PIN 15
-T- C E
SEATING PLANE
NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIMENSION R DOES NOT INCLUDE MOLD FLASH OR PROTRUSIONS. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH OR PROTRUSIONS. 5. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 (0.250). 6. DELETED 7. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE PROTRUSION SHALL BE 0.003 (0.076) TOTAL IN EXCESS OF THE D DIMENSION. AT MAXIMUM MATERIAL CONDITION. INCHES MIN MAX 0.681 0.694 0.784 0.792 0.173 0.181 0.024 0.031 0.058 0.062 0.016 0.023 0.050 BSC 0.110 BSC 0.018 0.024 1.078 1.086 0.148 0.151 0.416 0.426 0.110 BSC 0.503 REF MILLIMETERS MIN MAX 17.298 17.627 19.914 20.116 4.395 4.597 0.610 0.787 1.473 1.574 0.407 0.584 1.270 BSC 2.794 BSC 0.458 0.609 27.382 27.584 3.760 3.835 10.567 10.820 2.794 BSC 12.776 REF
Y
G
15X
7X
F
M
H
15X
D 0.010 (0.254) TPL
S
J 0.024 (0.610)
M
T
DIM A B C D E F G H J K Q R U Y
TV SUFFIX PLASTIC PACKAGE CASE 821C-04 ISSUE D
-T- B U A R K Y M -Q- -P- C E
SEATING PLANE
NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIMENSION R DOES NOT INCLUDE MOLD FLASH OR PROTRUSIONS. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH OR PROTRUSIONS. 5. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 (0.250). 6. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE PROTRUSION SHALL BE 0.003 (0.076) TOTAL IN EXCESS OF THE D DIMENSION. AT MAXIMUM MATERIAL CONDITION. INCHES MIN MAX 0.684 0.694 0.784 0.792 0.173 0.181 0.024 0.031 0.058 0.062 0.050 BSC 0.169 BSC 0.018 0.024 0.700 0.710 0.200 BSC 0.148 0.151 0.416 0.426 0.157 0.167 0.105 0.115 0.868 REF 0.625 0.639 MILLIMETERS MIN MAX 17.374 17.627 19.914 20.116 4.395 4.597 0.610 0.787 1.473 1.574 1.270 BSC 4.293 BSC 0.458 0.609 17.780 18.034 5.080 BSC 3.760 3.835 10.567 10.820 3.988 4.242 2.667 2.921 22.047 REF 15.875 16.231
V
PIN 1
PIN 15
S H
G
15X
D 0.010 (0.254)
M
T PQ
S
L
15X
J 0.024 (0.610)
M
T
DIM A B C D E G H J K L M R S U V Y
How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; P.O. Box 20912; Phoenix, Arizona 85036. 1-800-441-2447 or 602-303-5454 MFAX: RMFAX0@email.sps.mot.com - TOUCHTONE 602-244-6609 INTERNET: http://Design-NET.com
JAPAN: Nippon Motorola Ltd.; Tatsumi-SPD-JLDC, 6F Seibu-Butsuryu-Center, 3-14-2 Tatsumi Koto-Ku, Tokyo 135, Japan. 03-81-3521-8315 ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852-26629298
16
*MC33293A/D*
MOTOROLA ANALOG IC DEVICE DATA
MC33293A/D

▲Up To Search▲

Price & Availability of MC33293AT

	To Download MC33293AT Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .