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MIC23254
4MHz Dual 400mA Synchronous Buck Regulator with Low Input Voltage and HyperLight LoadTM
General Description
Features
The MIC23254 is a low-input voltage, high-efficiency 4MHz * Low input voltage range: 2.5V to 5.5V dual 400mA synchronous buck regulator with HyperLight * Dual output current 400mA/400mA LoadTM mode. HyperLight LoadTM provides very-high * Up to 94% peak efficiency and 85% efficiency at 1mA efficiency at light loads and ultra-fast transient response * 33A dual quiescent current which is perfectly suited for supplying processor core * 1H inductor with a 4.7F capacitor voltages. An additional benefit of this proprietary * 4MHz in PWM operation architecture is very-low output ripple voltage throughout the entire load range with the use of small output * Ultra-fast transient response capacitors. MIC23254 operates from an input voltage * Low voltage output ripple down to 2.5V for low battery states. The MIC23254 has a * 20mVpp in HyperLight LoadTM mode (R) tiny 2mm x 2mm Thin MLF package that saves precious * 3mV output voltage ripple in full PWM mode board space by requiring only 6 additional external * 0.01A shutdown current components to drive both outputs up to 400mA each. * Fixed output:10-pin 2mm x 2mm Thin MLF(R) The device is designed for use with a 1H inductor and a * -40C to +125C junction temperature range 4.7F output capacitor that enables a sub-1mm height. The MIC23254 has a very-low quiescent current of 33A with both outputs enabled and can achieve over 85% Applications efficiency at 1mA. At higher loads the MIC23254 provides a * Mobile handsets constant switching frequency around 4MHz while providing * Portable media players peak efficiencies over 90%. * Portable navigation devices (GPS) The MIC23254 fixed output voltage option is available in a * WiFi/WiMax/WiBro modules 10-pin 2mm x 2mm Thin MLF(R). The MIC23254 is designed * Digital cameras to operate over the junction operating range from -40C to * Wireless LAN cards +125C. * USB Powered Devices Data sheets and support documentation can be found on Micrel's web site at: www.micrel.com. ____________________________________________________________________________________________________________
Typical Application
Efficiency VOUT = 1.8V
100 90 80 VIN = 3.0V
EFFICIENCY (%)
70 60 50 40 30 20 10 0 1 10 100 1000 L = 1H COUT = 4.7F VIN = 4.2V VIN = 2.7V VIN = 3.6V
LOAD (mA)
HyperLight Load is a trademark of Micrel, Inc. MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc. Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1 (408) 944-0800 * fax + 1 (408) 474-1000 * http://www.micrel.com
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MIC23254
Ordering Information
Part Number MIC23254-GCYMT
Notes: 1. Thin MLF(R) is GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Marking Code GCW
Nominal Output Voltage 1 1V
Nominal Output Voltage 2 1.8V
Junction Temperature Range -40 to +125C
Package 10-Pin 2mm x 2mm Thin MLF(R)
Lead Finish Pb-Free
Pin Configuration
SNS1 EN1 AGND SW1 PGND 1 2 3 4 5 10 SNS2 9 8 7 6 EN2 AVIN SW2 VIN
(R) 10-Pin 2mm x 2mm Thin MLF (MT) Fixed Output (Top View)
Pin Description
Pin Number (Fixed) 1 2 3 4 5 6 7 8 9 10 Pin Name SNS1 EN1 AGND SW1 PGND VIN SW2 AVIN EN2 SNS2 Pin Function Sense 1 (Input): Connect to VOUT1 as close to output capacitor as possible to sense output 1 voltage. Enable 1 (Input): Logic low will shut down output 1. Logic high powers up output 1. Do not leave unconnected. Analog Ground. Must be connected externally to PGND. Switch Node 1 (Output): Internal power MOSFET output. Power Ground. Supply Voltage (Power Input): Requires close bypass capacitor to PGND. Switch Node 2 (Output): Internal power MOSFET output. Supply Voltage (Power Input): Analog control circuitry. Connect to VIN. Enable 2 (Input): Logic low will shut down output 2. Logic high powers up output 2. Do not leave unconnected. Sense 2 (Input): Connect to VOUT2 as close to output capacitor as possible to sense output 2 voltage.
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Absolute Maximum Ratings(1)
Supply Voltage (VIN) ........................................ -0.3V to +6V Output Switch Voltage (VSW) ............................. -0.3V to 6V Sense Input Voltage (VSNS1, VSNS2) ................... -0.3V to VIN Logic Input Voltage (VEN1, VEN2) ........................ -0.3V to VIN Storage Temperature Range (Ts)..............-65C to +150C ESD Rating(3) ................................................. ESD Sensitive
Operating Ratings(2)
Supply Voltage (VIN)......................................... 2.5V to 5.5V Sense Input Voltage (VSNS1, VSNS2) ........................ 0V to VIN Logic Input Voltage (VEN1, VEN2) ............................. 0V to VIN Junction Temperature (TJ) ..................-40C TJ +125C Thermal Resistance 2mm x 2mm Thin MLF-10 (JA) .........................70C/W
Electrical Characteristics(4)
TA = 25C with VIN = VEN1 = VEN2 = 3.6V; L = 1H; COUT = 4.7F; IOUT = 20mA; only one channel power is enabled, unless otherwise specified. Bold values indicate -40C< TJ < +125C.
Parameter Under-Voltage Lockout Threshold UVLO Hysteresis Quiescent Current Shutdown Current Output Voltage Accuracy Current Limit in PWM Mode Output Voltage Line Regulation Output Voltage Load Regulation PWM Switch ON-Resistance Frequency Soft-Start Time Enable Threshold Enable Input Current Over-Temperature Shutdown Over-Temperature Shutdown Hysteresis Condition (Turn-On) VOUT1, 2 (Both Enabled), IOUT1, 2 = 0mA , VSNS1,2 >1.2 x VOUT1, 2 Nominal VEN1, 2 = 0V; VIN = 5.5V VIN = 3.6V, ILOAD = 20mA SNS = 0.9 x VOUT NOM VIN = 3.6V to 5.5V, ILOAD = 20mA 20mA < ILOAD < 400mA, VIN = 3.6V ISW = 100mA PMOS ISW = -100mA NMOS ILOAD = 120mA VOUT = 90% 0.5 -2.5 0.410 0.62 0.4 0.5 0.6 0.8 4 260 0.9 0.1 160 20 Min. 2.3 Typ. 2.4 60 33 0.01 Max. 2.485 50 4 +2.5 1 Units V mV A A % A %/V % MHz s V A C C
1.2 2
Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. Human body model: 1.5k in series with 100pF. 4. Specification for packaged product only.
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Typical Characteristics
Quiescent Current vs. Input Voltage
50
Switching Frequency vs. Output Current
10.00
10
Switching Frequency vs. Output Current
L = 4.7H
QUIESCENT CURRENT (A)
45
SWITCHING FREQUENCY (MHz)
40 35 30 25 20 15 10 5 0 2.5 3 3.5 4 4.5 5 5.5 L = 1H COUT = 4.7F
VIN = 2.5V
SWITCHING FREQUENCY (MHz)
4MHz
1.00 VIN = 3V VIN = 5V 0.10 VIN = 4.2V VOUT = 1.8V L = 1H COUT = 4.7F 0.1 1
1 L = 1H
0.1
L = 2.2H VIN = 3.6V VOUT = 1.8V COUT = 4.7F
VIN = 3.6V 0.01 0.001 0.01
0.01 1 10 100 1000
INPUT VOLTAGE (V)
LOAD CURRENT (A)
OUTPUT CURRENT (mA)
Frequency vs. Temperature
5
1.9 1.88
Output Voltage vs. Output Current
1.90 1.88
Output Voltage vs. Input Voltage
OUTPUT VOLTAGE (V)
1.86
OUTPUT VOLTAGE (V)
1.86 IOUT = 200mA 1.84 1.82 1.80 1.78 1.76 1.74 1.72 IOUT = 400mA L = 1H COUT = 4.7F TA = 25C 4 4.5 5 5.5 IOUT = 20mA
FREQUENCY (MHz)
4.5
1.84 1.82 1.8 1.78 1.76 1.74 1.72 1.7 0.1 1 10 VIN = 2.5V
VIN = 4.2V
4
3.5
VIN = 3.6V
L = 1H COUT = 4.7F IOUT = 120mA -40 -20 0 20 40 60 80 100 120
3
TA = 25oC 100 1000
1.70 2.5 3 3.5
TEMPERATURE (C)
OUTPUT CURRENT (mA)
INPUT VOLTAGE (V)
Output Voltage vs. Temperature
1.9 1.88 VIN = 5V VIN = 4.2V
Enable Threshold vs. Temperature
1.2
Enable Threshold vs. Input Voltage
1.05
ENABLE THRESHOLD (V)
1
OUTPUT VOLTAGE (V)
1.86 1.84 1.82 1.8 1.78 1.76 1.74 1.72 1.7 -40
ENABLE THRESHOLD (V)
ENon 0.8 ENoff 0.6
1 ENon 0.95 ENoff 0.9
VIN = 3.6V
VIN = 2.5V L = 1H COUT = 4.7uF IOUT = 20mA
0.4
0.2
VIN = 3.6V L = 1H COUT = 4.7F -40 -20 0 20 40 60 80 100 120
0.85
TA = 25C L = 1H COUT = 4.7F 2.5 3 3.5 4 4.5 5 5.5
-20
0
20
40
60
80
100 120
0
0.8
TEMPERATURE (C)
TEMPERATURE (C)
INPUT VOLTAGE (V)
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Typical Characteristics (Continued)
Start-Up Voltage vs JunctionTemperature
2.5 2.45
MOSFET RDSon vs. Input Voltage
1.00 0.90
Current Limit vs. Input Voltage
0.9 0.8
MOSFET RESISTANCE (s)
INPUT VOLTAGE (V)
UVLOon 2.4 2.35 UVLOoff 2.3 2.25 2.2 -40 -20 0 20 40 60 80 100 120
0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 2.5 3 3.5 4 4.5 5 TA = 25C P-CHANNEL
CURRENT LIMIT (A)
0.80
N-CHANNEL
0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 2.5 3 3.5 4 4.5 5 5.5 TA = 25C L = 1H COUT = 4.7F
TEMPERTURE ( C)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Efficiency VOUT = 1V
100% 90% 80% VIN = 2.7V VIN = 3V
Efficiency VOUT = 1.8V
100 90 80 VIN = 3.0V
Efficiency VOUT = 1.8V (With Various Inductors)
100 90 80 L = 1.5H
EFFICIENCY (%)
70%
EFFICIENCY (%)
EFFICIENCY (%)
60% 50% 40% 30% 20% 10% 0% 1 L = 1H COUT = 4.7F 10 100 1000 VIN = 3.6V VIN = 4.2V
70 60 50 40 30 20 10 0 1 10 100 1000 L = 1H COUT = 4.7F VIN = 4.2V VIN = 2.7V VIN = 3.6V
70 60 50 40 30 20 10 0 1 10 100 1000 VIN = 3.6V COUT = 4.7F L = 0.47H L = 1.0H
OUTPUT CURRENT (mA)
LOAD (mA)
LOAD (mA)
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Functional Characteristics
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Functional Characteristics (Continued)
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Functional Characteristics (Continued)
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Functional Diagram
MIC23254 Simplified Fixed Output Block Diagram
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Functional Description
VIN The VIN provides power to the internal MOSFETs for the switch mode regulator along with the current limit sensing. The VIN operating range is 2.5V to 5.5V so an input capacitor with a minimum of 6.3V voltage rating is recommended. Due to the high switching speed, a minimum of 2.2F bypass capacitor placed close to VIN and the power ground (PGND) pin is required. Based upon size, performance and cost, a TDK C1608X5R0J475K, size 0603, 4.7F ceramic capacitor is highly recommended for most applications. Refer to the layout recommendations for details. AVIN The analog VIN (AVIN) provides power to the analog supply circuitry. AVIN and VIN must be tied together. Careful layout should be considered to ensure high frequency switching noise caused by VIN is reduced before reaching AVIN. A 0.01F bypass capacitor placed as close to AVIN as possible is recommended. See layout recommendations for details. EN1/EN2 The enable pins (EN1 and EN2) control the on and off states of outputs 1 and 2, respectively. A logic high signal on the enable pin activates the output voltage of the device. A logic low signal on each enable pin deactivates the output. MIC23254 features built-in soft-start circuitry that reduces in-rush current and prevents the output voltage from overshooting at start up. SW1/SW2 The switching pin (SW1 or SW2) connects directly to one end of the inductor (L1 or L2) and provides the current path during switching cycles. The other end of the inductor is connected to the load and SNS pin. Due to the high speed switching on this pin, the switch node should be routed away from sensitive nodes. SNS1/SNS2 The SNS pin (SNS1 or SNS2) is connected to the output of the device to provide feedback to the control circuitry. A minimum of 2.2F bypass capacitor should be connected in shunt with each output. Based upon size, performance and cost, a TDK C1608X5R0J475K, size 0603, 4.7F ceramic capacitor is highly recommended for most applications. In order to reduce parasitic inductance, it is good practice to place the output bypass capacitor as close to the inductor as possible. The SNS connection should be placed close to the output bypass capacitor. Refer to the layout recommendations for more details. PGND The power ground (PGND) is the ground path for the high current in PWM mode. The current loop for the power ground should be as small as possible and separate from the Analog ground (AGND) loop. Refer to the layout recommendations for more details. AGND The signal ground (AGND) is the ground path for the biasing and control circuitry. The current loop for the signal ground should be separate from the Power Ground (PGND) loop. Refer to the layout recommendations for more details.
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MIC23254 The MIC23254 was designed for use with an inductance range from 0.47H to 4.7H. Typically, a 1H inductor is recommended for a balance of transient response, efficiency and output ripple. For faster transient response a 0.47H inductor may be used. For lower output ripple, a 4.7H is recommended. Maximum current ratings of the inductor are generally given in two methods; permissible DC current and saturation current. Permissible DC current can be rated either for a 40C temperature rise or a 10% to 20% loss in inductance. Ensure the inductor selected can handle the maximum operating current. When saturation current is specified, make sure that there is enough margin so that the peak current of the inductor does not cause it to saturate. Peak current can be calculated as follows:
1 - VOUT / VIN IPEAK = IOUT + VOUT 2 x f x L
Applications Information
The MIC23254 is designed for high performance with a small solution size. With a dual 400mA output inside a tiny 2mm x 2mm Thin MLF(R) package and requiring only six external components, the MIC23254 meets today's miniature portable electronic device needs. While small solution size is one of its advantages, the MIC23254 is big in performance. Using the HyperLight LoadTM switching scheme, the MIC23254 is able to maintain high efficiency throughout the entire load range while providing ultra-fast load transient response. Even with all the given benefits, the MIC23254 can be as easy to use as linear regulators. The following sections provide an over view of implementing MIC23254 into related applications Input Capacitor A minimum of 2.2F ceramic capacitor should be placed close to the VIN pin and PGND pin for bypassing. A TDK C1608X5R0J475K, size 0603, 4.7F ceramic capacitor is recommended based upon performance, size and cost. A X5R or X7R temperature rating is recommended for the input capacitor. Y5V temperature rating capacitors, aside from losing most of their capacitance over temperature, can also become resistive at high frequencies. This reduces their ability to filter out high-frequency noise. Output Capacitor The MIC23254 was designed for use with a 2.2F or greater ceramic output capacitor. Increasing the output capacitance will lower output ripple and improve load transient response but could increase solution size or cost. A low equivalent series resistance (ESR) ceramic output capacitor such as the TDK C1608X5R0J475K, size 0603, 4.7F ceramic capacitor is recommended based upon performance, size and cost. Either the X7R or X5R temperature rating capacitors are recommended. The Y5V and Z5U temperature rating capacitors, aside from the undesirable effect of their wide variation in capacitance over temperature, become resistive at high frequencies. Inductor Selection Inductor selection will be determined by the following (not necessarily in the order of importance): 1. 2. 3. 4. Inductance Rated current value Size requirements DC resistance (DCR)
As shown by the previous calculation, the peak inductor current is inversely proportional to the switching frequency and the inductance; the lower the switching frequency or the inductance the higher the peak current. As input voltage increases the peak current also increases. The size of the inductor depends on the requirements of the application. Refer to the Application Circuit and Bill of Material for details. DC resistance (DCR) is also important. While DCR is inversely proportional to size, DCR can represent a significant efficiency loss. Refer to the Efficiency Considerations. Compensation The MIC23254 is designed to be stable with a 0.47H to 4.7H inductor with a minimum of 2.2F ceramic (X5R) output capacitor. Efficiency Considerations Efficiency is defined as the amount of useful output power, divided by the amount of power supplied:
VOUT x IOUT Efficiency Loss = 1 - VOUT x IOUT + L_PD x 100
Maintaining high efficiency serves two purposes. It reduces power dissipation in the power supply, reducing the need for heat sinks and thermal design considerations and it reduces consumption of current for battery powered applications. Reduced current draw from a battery increases the devices operating time and is critical in hand held devices.
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Micrel, Inc. There are two types of losses in switching converters; DC losses and switching losses. DC losses are simply the power dissipation of I2R. Power is dissipated in the high side switch during the on cycle. Power loss is equal to the high-side MOSFET RDSON multiplied by the Switch Current squared. During the off cycle, the low side N-channel MOSFET conducts, also dissipating power. Device operating current also reduces efficiency. The product of the quiescent (operating) current and the supply voltage is another DC loss. The current required driving the gates on and off at a constant 4MHz frequency and the switching transitions make up the switching losses.
Efficiency VOUT = 1.8V
100 90 80 VIN = 3.0V
MIC23254 From that, the loss in efficiency due to inductor resistance can be calculated as follows:
VOUT x IOUT Efficiency Loss = 1 - VOUT x IOUT + L_PD x 100
70 60 50 40 30 20 10 0 1 10 100 1000 L = 1H COUT = 4.7F VIN = 4.2V VIN = 2.7V VIN = 3.6V
LOAD (mA)
The figure above shows an efficiency curve. From no load to 100mA, efficiency losses are dominated by quiescent current losses, gate drive and transition losses. By using the HyperLight LoadTM mode the MIC23254 is able to maintain high efficiency at low output currents. Over 100mA, efficiency loss is dominated by MOSFET RDSON and inductor losses. Higher input supply voltages will increase the Gate-to-Source threshold on the internal MOSFETs, thereby reducing the internal RDSON. This improves efficiency by reducing DC losses in the device. All but the inductor losses are inherent to the device. In which case, inductor selection becomes increasingly critical in efficiency calculations. As the inductors are reduced in size, the DC resistance (DCR) can become quite significant. The DCR losses can be calculated as follows: DCR Loss = IOUT2 x DCR
Efficiency loss due to DCR is minimal at light loads and gains significance as the load is increased. Inductor selection becomes a trade-off between efficiency and size in this case. HyperLight Load ModeTM The MIC23254 uses a minimum on and off time proprietary control loop (patented by Micrel). When the output voltage falls below the regulation threshold, the error comparator begins a switching cycle that turns the PMOS on and keeps it on for the duration of the minimumon-time. This increases the output voltage. If the output voltage is over the regulation threshold, then the error comparator turns the PMOS off for a minimum-off-time until the output drops below the threshold. The NMOS acts as an ideal rectifier that conducts when the PMOS is off. Using a NMOS switch instead of a diode allows for lower voltage drop across the switching device when it is on. The asynchronous switching combination between the PMOS and the NMOS allows the control loop to work in discontinuous mode for light load operations. In discontinuous mode, the MIC23254 works in pulse frequency modulation (PFM) to regulate the output. As the output current increases, the off-time decreases, thus providing more energy to the output. This switching scheme improves the efficiency of MIC23254 during light load currents by only switching when it is needed. As the load current increases, the MIC23254 goes into continuous conduction mode (CCM) and switches at a frequency centered at 4MHz. The equation to calculate the load when the MIC23254 goes into continuous conduction mode may be approximated by the following formula:
(VIN - VOUT ) x D ILOAD > 2L x f
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Micrel, Inc. As shown in the previous equation, the load at which MIC23254 transitions from HyperLight LoadTM mode to PWM mode is a function of the input voltage (VIN), output voltage (VOUT), duty cycle (D), inductance (L) and frequency (f). This is illustrated in the graph below. Since the inductance range of MIC23254 is from 0.47H to 4.7H, the device may then be tailored to enter HyperLight LoadTM mode or PWM mode at a specific load current by selecting the appropriate inductance. For example, in the graph below, when the inductance is 4.7H the MIC23254 will transition into PWM mode at a load of approximately 5mA. Under the same condition, when the inductance is 1H, the MIC23254 will transition into PWM mode at approximately 70mA.
Switching Frequency vs. Output Current
10 L = 4.7H
MIC23254 Thermal circuits can be considered using these same rules and can be drawn similarly replacing current sources with Power dissipation (in Watts), Resistance with Thermal Resistance (in C/W) and Voltage sources with temperature (in C):
SWITCHING FREQUENCY (MHz)
4MHz
Now replacing the variables in the equation for Vx, we can find the junction temperature (TJ) from power dissipation, ambient temperature and the known thermal resistance of the PCB (RCA) and the package (RJC):
TJ = PDISS (R JC + R CA ) + TAMB
1 L = 1H
0.1
L = 2.2H VIN = 3.6V VOUT = 1.8V COUT = 4.7F
As can be seen in the diagram, total thermal resistance RJA = RJC + RCA. Hence this can also be written:
1000
0.01 1 10 100
TJ = PDISS (R JA ) + TAMB
OUTPUT CURRENT (mA)
Power Dissipation Considerations As with all power devices, the ultimate current rating of the output is limited by the thermal properties of the package and the PCB it is mounted on. There is a simple, ohms law type relationship between thermal resistance, power dissipation and temperature which are analogous to an electrical circuit:
PDISS can be calculated thus:
1 PDISS = POUT ( - 1)
Where = Efficiency taken from efficiency curves RJC and RJA are found in the operating ratings section of the datasheet.
From this simple circuit we can calculate Vx if we know Isource, Vz and the resistor values, Rxy and Ryz using the equation:
Vx = Isource (Rxy + Ryz) + Vz
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Example: The MIC23254 is intended to drive a 200mA load at 1.8V, a 200mA load at 1.0V, and is placed on a printed circuit board which has a ground plane area of at least 25mm square. The Voltage source is a Li-ion battery with a lower operating threshold of 3V and the ambient temperature of the assembly can be up to 50C.
MIC23254 PIND = 0.0076W PDISS = 0.115 - 2*(0.0076) = 0.1W Therefore: TJ = 0.1W * (70 C/W) + 50C TJ = 57C This is well below the maximum 125C.
Summary of variables: IOUT1 = 0.2A, IOUT2 = 0.2A VOUT1 = 1.0V, VOUT2 = 1.8V VIN = 3V to 4.2V Inductor DCR = 190m TAMB = 50C RJA = 70C/W from Datasheet
1 @ 200mA = 78%, 2 @ 200mA = 86%, (worst case
with VIN=4.2V from the Typical Characteristics Efficiency vs. Load graphs)
PDISS = 1.0 0.2 (
PDISS= 0.115W
1 1 - 1) + 1.8 0.2 ( - 1) 0.78 0.86
Subtracting the power loss from the inductors: PIND1 = PIND2 = Inductor DCR * IOUT2 PIND = 0.19*0.22
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MIC23254 Typical Application Circuit
Bill of Materials
Item C1, C2, C3 C4 R1, R2 Part Number C1608X5R0J475K VJ0603Y103KXXAT CRCW06031002FKEA LQM21PN1R0MC0D LQH32CN1R0M33 LQM31PN1R0M00 L1, L2 GLF251812T1R0M LQM31PNR47M00 MIPF2520D1R5 EPL2010-102 U1
Notes:
Manufacturer TDK
(1)
Description 4.7F Ceramic Capacitor, 6.3V, X5R, Size 0603 0.01F Ceramic Capacitor, 25V, X7R, Size 0603 10k, 1%, 1/16W, Size 0603 1H, 0.8A, 190m, L2mm x W1.25mm x H0.5mm 1H, 1A, 60m, L3.2mm x W2.5mm x H2.0mm 1H, 1.2A, 120m, L3.2mm x W1.6mm x H0.95mm 1H, 0.8A, 100m, L2.5mm x W1.8mm x H1.35mm 0.47H, 1.4A, 80m, L3.2mm x W1.6mm x H0.85mm 1.5H, 1.5A, 70m, L2.5mm x W2mm x H1.0mm 1.0H, 1.0A, 86m, L2.0mm x W1.8mm x H1.0mm Low-Voltage, 4MHz Dual 400mA Fixed-Output Buck Regulator with HyperLight LoadTM Mode
Qty 3 1 Optional
Vishay(2) Vishay
(2) (3) (3)
Murata Murata TDK
Murata(3)
(1) (3)
2
Murata
FDK(4) Coilcraft(5) Micrel, Inc.(6)
MIC23254-GCYMT
1
1. TDK: www.tdk.com. 2. Vishay: www.vishay.com. 3. Murata: www.murata.com. 4. FDK: www.fdk.co.jp. 5. Coilcraft: www.coilcraft.com.
6. Micrel, Inc: www.micrel.com.
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PCB Layout Recommendations
Top Layer
Bottom Layer
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Package Information
10-Pin 2mm x 2mm Thin MLF (MT)
(R)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. (c) 2010 Micrel, Incorporated.
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