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Global Mixed-mode Technology Inc.
G914
150mA Low-Dropout Linear Regulators
Features
Low, 52A Ground Current Guaranteed 150mA Output Current Dropout Voltage is 100mV @ 50mA Load Over-Temperature Protection and Short-Circuit Protection Adjustable Mode: from 2.5V to 5.5V Max. Supply Current in Shutdown Mode < 1A Low Output Noise is 170 VRMS
General Description
The G914 is a low supply current, low dropout linear regulator that comes in a space saving SOT23-5 package. The supply current at no-load is 52A. In the shutdown mode, the maximum supply current is less than 1A. Operating voltage range of the G914 is from 2.5V to 5.5V. The over-current protection limit is set at 370mA typical and 150mA minimum. An overtemperature protection circuit is built-in in the G914 to prevent thermal overload. These power saving features make the G914 ideal for use in the battery-powered applications such as notebook computers, cellular phones, and PDA's. The G914 is a adjustable output version in a small SOT 23-5 package.
Applications
Notebook Computers Cellular Phones PDAs Digital still Camera and Video Recorders Hand-Held Devices Bar Code Scanners
Ordering Information
PART MARKING VOLTAGE
G914 14 Adjustable
TEMP. RANGE
-40C~ +85C
PINPACKAGE
SOT 23-5
Pin Configuration
IN
1
5
OUT
IN
OUT R1
OUTPUT VOLTAGE
G914
BATTERY C IN 1F SHDN GND
ADJ R2 470pF COUT 1F
GND
2
G914
SHDN
3
4
ADJ
SOT23-5
Adjustable mode
VOUT =1.250 X ( R2/R1+1)
Ver 0.1 Preliminary Nov 05, 2001
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Absolute Maximum Ratings
VIN to GND..........................................-0.3V to +7V Output Short-Circuit Duration..........................Infinite SET to GND.........................................-0.3V to +7V SHDN to GND....................................-0.3V to +7V SHDN to IN.........................................-7V to +0.3V OUT to GND..............................-0.3V to (VIN + 0.3V)
G914
Continuous Power Dissipation (TA = +25C) SOT23-5..................................................568 mW Operating Temperature Range............-40C to +85C Junction Temperature..................................+150C JA......................................................220C/Watt Storage Temperature Range.............-65C to +160C Lead Temperature (soldering, 10sec)..............+300C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Electrical Characteristics
(VIN = VOUT +1V; V SHDN = VIN; CIN = COUT = 1F = TA = TJ = +25C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Voltage (Note 2) Output Voltage Accuracy Adjustable Output Voltage Range (Note 3) Maximum Output Current Current Limit Ground Pin Current VIN VOUT VOUT ILIM IQ VDROP VLNR VLDR Variation from specified VOUT, IOUT=1mA Note2 -2 2.5 150 370 52 2 100 340 0.1 30 40 192 170 2 0.4 TA = +25C TA = +25C TA = +25C 0.007 0.06 5 150 15 0.1 1 20 CADJ = 470pF CADJ = 10nF 80 5.5 2 5.5 V % V mA mA A
Dropout Voltage (Note 3) Line Regulation Load Regulation Output Voltage Temperature Coefficient Output Voltage Noise (10HZ to 100KHZ) SHUTDOWN
SHDN Input Threshold SHDN Input Bias Current
VOUT = 0V ILOAD = 0mA ILOAD = 150mA IOUT = 1mA IOUT = 50mA IOUT =150mA VIN=VO +0.1V to 5.5V, IOUT = 1mA IOUT = 0mA to 150mA
mV %/V mV ppm/C VRMS
VO / T IOUT = 40mA, TJ = 25C to 125C en IL = 150mA
VIH VIL I SHDN IQSHDN IADJ TSHDN TSHDN
Regulator enabled Regulator shutdown V SHDN = VIN VOUT = 0V VADJ = 1.3V
V A A nA C C
Shutdown Supply Current ADJ INPUT ADJ Input Leakage Current THERMAL PROTECTION Thermal Shutdown Temperature Thermal Shutdown Hysteresis
Note 1: Limits is 100% production tested at TA= +25C. Low duty pulse techniques are used during test to maintain junction temperature as close to ambient as possible. Note 2: VIN (min) = VOUT +VDROP. Note 3: The dropout voltage is defined as (VIN-VOUT) when VOUT is 100mV below the value of VOUT for VIN = VOUT +2V.
Ver 0.1 Preliminary Nov 05, 2001
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Pin Description
PIN
1 2 3
G914
NAME
IN GND
SHDN
FUNCTION
Regulator Input. Supply voltage can range from +2.5V to +5.5V. Bypass with 1F to GND Ground. This pin also functions as a heatsink. Solder to large pads or the circuit board ground plane to maximize thermal dissipation. Active-Low Shutdown Input. A logic low reduces the supply current to less than 1A. Connect to IN for normal operation. Adjust (Input): Adjustable regulator feedback input. It can connect to an external resistor divider for adjustable output voltage. It also must connect 470pF ceramic capacitor from ADJ pin to GND for reduce output noise. Regulator Output. Fixed or adjustable from +2.5V to +5.5V. Sources up to 150mA. Bypass with a 1F, 0.2 typical ESR capacitor to GND.
4
ADJ
5
OUT
Detailed Description
The block diagram of the G914 is shown in Figure 1. It consists of an error amplifier, 1.25V bandgap reference, PMOS output transistor, shutdown logic, over current protection circuit, and over temperature protection circuit. The G914 can be adjusted to a specific output voltage by using two external resistors (Figure 2). The resistors set the output voltage based on the following equation: R2 VOUT =1.250V X +1 R1
This equation is correct due to the configuration of the bandgap reference. The bandgap voltage is relative to the output, as seen in the block diagram. Traditional regulators normally have the reference voltage relative to ground and have a different VOUT equation. Resistor values are not critical because ADJ (adjust)has a high input impedance, but for best results use resistors of 470k or less. A capacitor from ADJ to ground provides greatly improved noise performance.
IN
SHDN
SHUTDOWN LOGIC ERROR AMP.
OVER TEMP. & OVER CURRENT PROTECTION 1.25V ref
OUT
ADJ GND
Figure 1. Functional Diagram
Ver 0.1 Preliminary Nov 05, 2001
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
IN BATTERY CIN 1F G914 ADJ SHDN GND R2 470pF COUT 1F RL OUT R1 OUTPUT VOLTAGE
G914
of the chosen package to the ambient air. In the case of a SOT23-5 package, the thermal resistance is typically 220oC/Watt. The die attachment area of the G914's lead frame is connected to pin 2, which is the GND pin. Therefore, the GND pin of G914 can carry away the heat of the G914 die very effectively. To improve the power dissipation, connect the GND pin to ground using a large ground plane near the GND pin.
Applications Information
Figure 2. Adjustable Output Using External Feedback Resistors Over Current Protection The G914 use a current mirror to monitor the output current. A small portion of the PMOS output transistor's current is mirrored onto a resistor such that the voltage across this resistor is proportional to the output current. This voltage is compared against the reference voltage. Once the output current exceeds the limit, the PMOS output transistor enters constant current mode. The current is set to 370mA typically. Over Temperature Protection To prevent abnormal temperature from occurring, the G914 has a built-in temperature monitoring circuit. When it detects the temperature is above 150oC, the output transistor is turned off. When the IC is cooled down to below 135oC, the output is turned on again. In this way, the G914 will be protected against abnormal junction temperature during operation. Shutdown Mode When the SHDN pin is connected a logic low voltage, the G914 enters shutdown mode. All the analog circuits are turned off completely, which reduces the current consumption to only the leakage current. The output is disconnected from the input. When the output has no load at all, the output voltage will be discharged to ground through the internal resistor voltage divider. Operating Region and Power Dissipation Since the G914 is a linear regulator, its power dissipation is always given by P = IOUT (VIN - VOUT). The maximum power dissipation is given by: PD(MAX) = (TJ-TA)/JA,=150oC-25oC/220oC/W= 568mW Where (TJ-TA) is the temperature difference the G914 die and the ambient air,JA, is the thermal resistance Capacitor Selection and Regulator Stability Normally, use a 1F capacitor on the input and a 1F capacitor on the output of the G914. Larger input capacitor values and lower ESR provide better supply-noise rejection and transient response. A highervalue input capacitor (10F) may be necessary if large, fast transients are anticipated and the device is located several inches from the power source. Power-Supply Rejection and Operation from Sources Other than Batteries The G914 is designed to deliver low dropout voltages and low quiescent currents in battery powered systems. Power-supply rejection is 42dB at low frequencies. When operating from sources other than batteries, improve supply-noise rejection and transient response by increasing the values of the input and output capacitors, and using passive filtering techniques. Load Transient Considerations The G914 load-transient response graphs show two components of the output response: a DC shift of the output voltage due to the different load currents, and the transient response. Typical overshoot for step changes in the load current from 0mA to 100mA is 12mV. Increasing the output capacitor's value and decreasing its ESR attenuates transient spikes. Input-Output (Dropout) Voltage A regulator's minimum input-output voltage differential (or dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this will determine the useful end-of-life battery voltage. Because the G914 use a P-channel MOSFET pass transistor, their dropout voltage is a function of RDS(ON) multiplied by the load current.
Ver 0.1 Preliminary Nov 05, 2001
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Layout Guide An input capacitance of 1F is required between the G914 input pin and ground (the amount of the capacitance may be increased without limit), This capacitor must be located a distance of not more than 1cm from the input and return to a clean analog ground. Input capacitor can filter out the input voltage spike caused by the surge current due to the inductive effect of the package pin and the printed circuit board's
G914
routing wire. Otherwise, the actual voltage at the IN pin may exceed the absolute maximum rating. The output capacitor also must be located a distance of not more than 1cm from output to a clean analog ground. Because it can filter out the output spike caused by the surge current due to the inductive effect of the package pin and the printed circuit board's routing wire. Figure 3 is suggested PCB layout of G914.
Figure 3. Suggested PCB Layout
*Distance between pin & capacitor must no more than 1cm
Ver 0.1 Preliminary Nov 05, 2001
TEL: 886-3-5788833 http://www.gmt.com.tw
5
Global Mixed-mode Technology Inc.
Package Information
D C L
G914
E
H
e1 e
1
A A2 A1
b
Note: 1. Package body sizes exclude mold flash protrusions or gate burrs 2. Tolerance 0.1000 mm (4mil) unless otherwise specified 3. Coplanarity: 0.1000mm 4. Dimension L is measured in gage plane SYMBOLS
A A1 A2 b C D E e e1 H L 1
MIN
1.00 0.00 0.70 0.35 0.10 2.70 1.40 --------2.60 0.37 1
DIMENSIONS IN MILLIMETERS NOM
1.10 ----0.80 0.40 0.15 2.90 1.60 1.90(TYP) 0.95 2.80 -----5
MAX
1.30 0.10 0.90 0.50 0.25 3.10 1.80 --------3.00 ----9
Taping Specification
Feed Direction SOT23-5 Package Orientation
Ver 0.1 Preliminary Nov 05, 2001
TEL: 886-3-5788833 http://www.gmt.com.tw
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