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ST662A
DC-DC CONVERTER FROM 5V TO 12V, 0.03A FOR FLASH MEMORY PROGRAMMING SUPPLY
s s s
s s
s
OUTPUT VOLTAGE: 12V 5% SUPPLY VOLTAGE RANGE: 4.5V TO 5.5V GUARANTEED OUTPUT CURRENT UP TO 30mA VERY LOW QUIESCENT CURRENT: 100A LOGIC CONTROLLED ELECTRONIC SHUTDOWN: 1A JUST CAPACITORS NEEDED (NO INDUCTOR)
DIP-8
DESCRIPTION The ST662A is a regulated charge pump DC-DC converter. It provides 12V 5% output voltage to program byte-wide flash memory, and can supply 30mA output current from input as low as 4.75V A logic controlled shut down pin that interfaces directly with microprocessor reduces the sypply current to only 1A
SO-8
TYPICAL APPLICATION CIRCUIT
June 1997
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ST662A
ABSOLUTE MAXIMUM RATINGS
Symbol Vc c SHDN Io Pt ot To p T stg DC Input Voltage to GND Shutdown Voltage Output Current Continuous Power Dissipation Operating Ambient Temperature Range (for AC SERIES) (for AB SERIES) Storage Temperature Range Parameter Value -0.3 to 6 -0.3 to VCC +0.3 50 500 0 to 70 - 40 to 85 - 40 to 150 Unit V V mA mW
o o o
C C C
Absolute Maximum Rating are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
CONNECTION DIAGRAM AND (top view)
PIN CONNECTIONS
Pin No 1 2 3 4 5 6 7 8 Symbol C1C1+ C2C2+ V CC V OUT G ND SHDN Name and Function Negative Terminal For The First Charge Pump Capacitor Positive Terminal For The First Charge Pump Capacitor Negative Terminal For The Second Charge Pump Capacitor Positive Terminal For The Second Charge Pump Capacitor Supply Voltage 12V Output Voltage VOUT = VCC When in Sshutdown Mode Ground Active High C-MOS logic level Shutdown Input. SHDN is internally pulled up to VCC. Connect to GND for Normal Operation. In Shutdown mode the charge pumps are turned off and VOUT = VCC
ORDERING NUMBERS
Type ST662AB ST662AC ST662ABN ST662ACN DIP-8 ST662ABD ST662ACD SO-8 (*)
(*) AVAILABLE IN TAPE AND REEL WITH "-TR" SUFFIX
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ST662A
ELECTRICAL CHARACTERISTICS (Refer to the test circuits, VCC = 4.5V to 5.5V Ta = Tmin to Tmax unless otherwise specified. Typical Value are referred at Ta = 25 oC)
Symbol Vo Vo I Q1 I Q2 I SH V il V ih fo R sw Parameter Output Voltage Output Voltage Quiescent Current Shutdown Current Shutdown Pin Current Shutdown Input Low Threshold Shutdown Input High Threshold Oscillator Frequency Power Efficecy VCC - VOUT Switch Impedance VCC = 5V, Io = 30 mA VCC = 5V, Io = 30 mA VSHDN = VCC = 5V, Io = 100 A 2.4 400 72 1 2 Test Conditions Io = 0 mA to 20 mA Io = 0 mA to 30 mA VCC = 4.75 to 5.5 V No Load, VSHDN = 0 No Load, VSHDN = VCC VSHDN = 0V, VCC = 5V VSHDN = VCC = 5V -50 Min. 11.4 11.4 Typ. 12 12 100 1 -12 0 Max. 12.6 12.6 500 10 -5 0.4 Unit V V A A A A V V KHz % K
Do not overload or short the Output to Ground. If the above conditions are observerd, the device may be damaged.
Output Voltage vs Temperature
Output Voltage vs Temperature
Supply Current vs Temperature
Supply Currernt vs Supply Voltage
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ST662A
SHDN Pin Current vs Temperature Output Voltage vs Shutdown Input Voltage
Output Voltage vs Shutdown Input Voltage
Output Voltage vs Shutdown Input Voltage
Test Circuit
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ST662A
DESCRIPTION The ST662 is an IC developed to provide a 12V regulated output 30mA from voltage input as low as 4.75 without any inductors. It is useful for a wide range of applications and its performances makes it ideal for flash memory programming supply. An evaluation kit is provided to facilitate the application. This include a single-side demo board designed for surface-mount components.The operating principle of ST662 (see fig. 1) is to charge C1 and C2 capacitor by closing the S1 switch (while S2 is opened) at the VCC voltage. After S1 will be opened and S2 closed so that C1 and C2 capacitors are placed in series one to each other, and both are in series with Vin.The sum of VC1 and VC2 and Vin is applied to the capacitor C4. This works as voltage tripler. An amplifier error checks the output voltage and blocks the oscillator if the output voltage is greater than 12V. The shutdown pin is internally pulled to VCC. When it is held low the output voltage rises to +12V. Fig.2 shows the transition time of the shut down pin when the VSHDN goes from 5V to 0V. Input logic levels of this input are CMOS compatible. Applying a logic high at this input, the VOUT oscillator will be blocked and the VOUT will reach theVIN value by D1. In this condition I CC will be Figure 2: Exiting Shutdown Figure 1: Operating Principle Circuit
low as 1A. The fig.3 shows the transition time of the shut down pin when the VSHDN goes from 0V to 5V.
Figure 3: Entering Shutdown
5V 0V SHDN 0V
5V
SHDN
Vout 5V
12V
12V Vout 5V
TIME= 20us/DIV, VERTICAL = 5V/DIV
NOTE: VCC = 5V, IOUT = 200A
TIME= 1ms/DIV, VERTICAL = 5V/DIV
NOTE: VCC = 5V, IOUT = 200A
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ST662A
APPLICATION CIRCUIT Based on fast charge/discharge of capacitors, this circuit involves high di/dt values limited only by Ron of switches. This implies a critical layout design due to the need to minimize inductive paths and place capacitors as close as possible to the device. A good layout design is strongly recommended for noise reason. For best performance, use very short connections to the capacitors and the values shown in table 1. Figure 4: KIT Lay-out C3 and C4 must have low ESR in order to minimize the output ripple. Their values can be reduced to 2F and 1F, respectively, when using ceramic capacitors, but must be of 10F or larger if aluminium electrolytic are chosen. C5 must be placed as close to the device as possible and could be omitted if very low output noise performance are not required. Fig 4 and Fig 5 show, respectively, our EVALUATION kit layout and the relatively electrical shematic.
Figure 5: Electrical Schematic
Table 1: List of Components
CAPACITOR Charge Pump C1 Charge Pump C2 Input C3 O utput C4 Decoupling C5 6/12 TYPE Ceramic Ceramic Electrolyt ic Tantalum Electrolyt ic Tantalum Ceramic VALUE (F) 0.22 0.22 4.7 4.7 0.1
ST662A
ST662A OUTPUT PERFORMANCE Output Voltage vs Output Current Efficency vs Output Current
Load Transient Response
Line Transient Response
Iout 20mA/div
SHDN Vin 1V/div
5.5V 4.5V
Vout Vout 100mV/div
Vout 200mV/div
TIME= 1ms/DIV
NOTE: VCC = 5V, IOUT = 0 to 30mA
TIME= 1ms/DIV
NOTE: VCC = 4.5 to 5.5V, IOUT = 30mA
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ST662A
HOW TO INCREASE OUTPUT CURRENT OR OUTPUT VOLTAGE CAPABILITY Current capability is limited by Ron of internal switches. It is possible to increase it connecting in parallel two or more ST662A devices; each one of them can supply 30mA. The figure 6 shows the electric schematic. The capacitors C3, C4 and C5 must be placed very close to the ICs on the board. If this is not possible, you can place two different capacitors, each of them of half value, very close to the respective integrated circuit. Fig. 8 show the Output Current capability of the proposed circuit. If an output voltage greater than 12V is required, it's possible to realize the circuit of the following diagram (figure 7). The relevant Output Current capability is shown in figure 9 in which is shown the output voltage vs load current.
Figure 6: Application Circuit for Two ST662A in Parallel
Table 2: List of Components
CAPACITOR C1A C2A C1B C2B C3 C4 C5 TYPE Ceramic Ceramic Ceramic Ceramic Electrolyt ic Tantalum Electrolyt ic Tantalum Ceramic VALUE (F) 0.22 0.22 0.22 0.22 10 10 0.22
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ST662A
Figure 7: Application Circuit for Output Voltage greater than 12V
Figure 8: Output Voltage for the Application with Two Device in Parallel
Figure 9: Output Voltage for Application with Output Voltage greater than 12V
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ST662A
Plastic DIP-8 MECHANICAL DATA
DIM. MIN. A a1 B B1 b b1 D E e e3 e4 F I L Z 0.44 3.3 1.6 0.017 8.8 2.54 7.62 7.62 7.1 4.8 0.130 0.063 0.38 0.7 1.39 0.91 0.5 0.5 9.8 0.346 0.100 0.300 0.300 0.280 0.189 0.015 1.65 1.04 mm TYP. 3.3 0.028 0.055 0.036 0.020 0.020 0.386 0.065 0.041 MAX. MIN. inch TYP. 0.130 MAX.
P001F
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ST662A
SO-8 MECHANICAL DATA
DIM. MIN. A a1 a2 a3 b b1 C c1 D E e e3 F L M S 3.8 0.4 4.8 5.8 1.27 3.81 4.0 1.27 0.6 8 (max.) 0.14 0.015 5.0 6.2 0.65 0.35 0.19 0.25 0.1 mm TYP. MAX. 1.75 0.25 1.65 0.85 0.48 0.25 0.5 45 (typ.) 0.188 0.228 0.050 0.150 0.157 0.050 0.023 0.196 0.244 0.025 0.013 0.007 0.010 0.003 MIN. inch TYP. MAX. 0.068 0.009 0.064 0.033 0.018 0.010 0.019
0016023
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ST662A
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsability for the consequence of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No s license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectonics. (c) 1997 SGS-THOMSON Microelectronics - Printed in Italy - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A .
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