G920
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G920
Global Mixed-mode Technology Inc.
150mA Micro-power LDO Regulators
Features
General Description
„Supply Current at No-Load is 55µA
„Minimum Over-Current Limit: 150mA
„Dropout Voltage is 70mV @ 50mA Load
„Built-in Over-Temperature Protection
„Fixed: 3.3V Output
„Max. Supply Current in Shutdown Mode < 1µA
„Output Noise is 210µVRMS from 10Hz to 1MHz
The G920 is a low supply current, low dropout linear
regulator that comes in a space saving SO-8 package.
The supply current at no-load is 55µA. In the shutdown mode, the maximum supply current is less than
1µA. operating voltage range of the G920 is from 3.6V
to 6.5V. The over-current protection limit is set at
250mA typical and 150mA minimum. An over-temperature protection circuit is built-in in the G920 to
prevent thermal overload. These power saving
features make the G920 ideal for use in the battery-powered applications such as notebook computers, cellular phones, and PDA’s.
Applications
„Notebook Computers
„Cellular Phones
„PDA
„Hand-Held Devices
Ordering Information
1
IN
2
TEMP. RANGE
PIN-PACKAGE
G920
-40°C~ +85°C
SOP- 8
Typical Operating Circuit
Pin Configuration
NC
PART
8
GND
7
GND
VIN
5V
IN
CIN
1µF
G920
OUT
3
6
GND
EN
4
5
GND
OUT
G920
EN
VOUT
3.3V/150mA
COUT
1µF
GND
8 Pin SOP
Fixed mode
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver 0.0 Preliminary
Mar 27, 2001
1
G920
Global Mixed-mode Technology Inc.
ABSOLUTE MAXIMUM RATINGS
SOT23-5 (derate 7.1mW/°C above +70°C).…..571 mW
Operating Temperature Range…………-40°C to +85°C
Junction Temperature……………………….……+150°C
θJA….…..……………….…………….…..…..140°C/Watt
Storage Temperature Range………….-65°C to +160°C
Lead
Temperature
(soldering,
10sec)..………….+300°C
VIN to GND…………………………………..-0.3V to +7V
Output Short-Circuit Duration………………….….Infinite
ADJ to GND.…………………………....…..-0.3V to +7V
EN to GND……………………..……..…….-0.3V to +7V
EN to IN….…………………………………..-7V to +0.3V
OUT to GND………………………..-0.3V to (VIN + 0.3V)
Continuous Power Dissipation (TA = +70°C)
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 = +3.6V, GND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
Input Voltage (Note 2)
Output Voltage
Adjustable Output Voltage Range (Note 3)
Maximum Output Current
Current Limit (Note 4)
VIN
VOUT
VOUT
Ground Pin Current
CONDITIONS
0mA ≤ IOUT ≤ 150mA, ADJ = GND
ILIM
IQ
ADJ = GND
ILOAD = 0mA
MIN
ILOAD = 50mA
145
2
IOUT = 1mA
Dropout Voltage (Note 5)
Line Regulation
∆VLNR
Load Regulation
∆VLDR
Output Voltage Noise
IOUT = 50mA
IOUT = 150mA
VIN=2.5V to 6.5V, ADJ tied to OUT,
IOUT = 1mA
IOUT = 0mA to 150mA
10 Hz to 1MHz
TYP MAX UNITS
3.6
6.5
3.234 3.300 3.366
VSET
6.5
150
250
55
120
70
230
120
0.1
ADJ = GND
0.011
ADJ tied to OUT
COUT = 1µF
COUT = 100µF
0.006
210
190
V
V
V
mA
mA
µA
mV
%/V
%/mA
µVRMS
SHUTDOWN
VIH
Regulator enabled
VIL
Regulator shutdown
EN Input Bias Current
IIH
VEN = VIN
Shutdown Supply Current
IIL
VOUT = 0V
EN Input Threshold
THERMAL PROTECTION
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
2.8
TA = +25°C
3
TA = TMAX
TA = +25°C
TA = TMAX
5
0.4
100
1
0.2
V
nA
µA
TSHDN
170
°C
∆TSHDN
20
°C
Note 1:Limits is 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control (SQC) Methods.
Note 2:Guaranteed by line regulation test.
Note 3:Adjustable mode only.
Note 4:Not tested. For design purposes, the current limit should be considered 150mA minimum to 420mA maximum.
Note 5:The dropout voltage is defined as (VIN - VOUT) when VOUT is 100mV below the value of VOUT for VIN = VOUT +2V.
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver 0.0 Preliminary
Mar 27, 2001
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G920
Global Mixed-mode Technology Inc.
TYPICAL PERFORMANCE CHARACTERISTICS
(VIN=+3.6V, CIN=1µF, COUT=1µF, TA =25 °C, unless otherwise noted.)
Output Voltage vs. Load Current
Ground Current vs. Load Current
Ground Current vs. Load Current
210
3.312
190
Ground Current ( μA)
Output Voltage (V)
Output voltage vs. Load Current
3.315
3.309
3.306
3.303
3.300
3.297
3.294
170
150
130
110
90
70
3.291
0
10
20
30
40
50
60
70
80
50
90 100 110 120 130 140 150
0
10
20
30
40
Load Current (mA)
Output Voltage vs. Input Voltage
2.0
1.5
1.0
0.5
0.0
3
4
90 100 110 120 130 140 150
5
ILOAD = 50mA
Supply Current ( μA)
Output Voltage (V)
No Load
2
80
130
120
110
100
90
80
70
60
50
40
30
20
10
0
3.0
1
70
Supply Current vs. Input Voltage
Output voltage vs. Load Current
0
60
Supply Current vs. Input Voltage
3.5
2.5
50
Load Current (mA)
6
Input Voltage (V)
ILOAD = 0A
0
Dropout Voltage vs. Load Current
1
2
3
4
Input Voltage (V)
5
6
7
Output Noise 10HZ to 1MHZ
Dropout Voltage (mV)
Dropout Voltage vs. Load Current
240
220
200
180
160
140
120
100
80
60
40
20
0
0
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
Load Current (mA)
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver 0.0 Preliminary
Mar 27, 2001
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Global Mixed-mode Technology Inc.
G920
TYPICAL PERFORMANCE CHARACTERISTICS (continue)
Line Transient
Load Transient
Load Transient
Load Transient
TEL: 886-3-5788833
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Ver 0.0 Preliminary
Mar 27, 2001
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G920
Global Mixed-mode Technology Inc.
Pin Description
PIN
NAME
FUNCTION
1
2
NC
IN
3
OUT
This is a NC pin, should be left unconnected.
Regulator Input. Supply voltage can range from +2.5V to +6.5V. Bypass with 1µF to GND.
Regulator Output. Sources up to 150mA. Bypass with a 1µF, <0.2Ω typical ESR capacitor to
4
EN
5,6,7,8
GND
GND.
Active-High Enable Input. A logic low reduces the supply current to less than 1µA. Connect to IN for
normal operation.
Ground. This pin also functions as a heatsink. Solder to large pads or the circuit board ground
plane to maximize thermal dissipation.
Detailed Description
output transistor, as a result the output voltage decreases until the feedback v41oltage is equal to 1.25V.
Similarly, when the feedback voltage is less than
1.25V, the error amplifier causes the output PMOS to
conductor more current to pull the feedback voltage up
to 1.25V. Thus, through this feedback action, the error
amplifier, output PMOS, and the voltage divider effectively form a unity-gain amplifier with the feedback
voltage force to be the same as the 1.25V bandgap
reference. The output voltage, VOUT, is then given by
the following equation:
VOUT = 1.25 (1 + R1/R2).
(1)
The block diagram of the G920 is shown in Figure 1. It
consists of an error amplifier, 1.25V bandgap reference, PMOS output transistor, internal feedback
voltage divider, shutdown logic, over current protection
circuit, and over temperature protection circuit.
The internal feedback voltage divider’s central tap is
connected to the non-inverting input of the error amplifier. The error amplifier compares non-inverting input
with the 1.25V bandgap reference. If the feedback
voltage is higher than 1.25V, the error amplifier’s output becomes higher so that the PMOS output transistor has a smaller gate-to-source voltage (VGS). This
reduces the current carrying capability of the PMOS
For the G920, the pre-set output voltage is 3.3V.
IN
EN
-
ERROR
AMP
SHUTDOWN
LOGIC
+
OVER CURRENT
PROTECT & DYNAMIC
FEEDBACK
OUT
R1
OVER TEMP.
PROTECT
1.25V
Vref
R2
GND
Figure 1. Functional Diagram
TEL: 886-3-5788833
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Ver 0.0 Preliminary
Mar 27, 2001
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G920
Global Mixed-mode Technology Inc.
Over Current Protection
The G920 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 1.25V reference.
Once the output current exceeds the limit, the PMOS
output transistor is turned off. Once the output transistor
is turned off, the current monitoring voltage decreases
to zero, and the output PMOS is turned on again. If the
over current condition persist, the over current protection circuit will be triggered again. Thus, when the output
is shorted to ground, the output current will be alternating between 0 and the over current limit. The typical
over current limit of the G920 is set to 250mA. Note that
the input bypass capacitor of 1µF must be used in this
case to 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 routing wire. Otherwise, the actual voltage at the IN pin may exceed the
absolute maximum rating.
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 G920 is a linear regulator, its power dissipation is always given by P = IOUT (VIN – VOUT). The
maximum power dissipation is given by:
PMAX = (TJ – TA)/θJA,
Where (TJ – TA) is the temperature difference the
G920 die and the ambient air, θJA, is the thermal resistance of the chosen package to the ambient air. In
the case of a SOT23-5 package, the thermal resistance is typically 140oC/Watt.
Applications Information
Capacitor Selection and Regulator Stability
Normally, use a 1µF capacitor on the input and a 1µF
capacitor on the output of the G920. Larger input capacitor values and lower ESR provide better supply-noise rejection and transient response. A
higher-value input capacitor (10µF) may be necessary if
large, fast transients are anticipated and the device is
located several inches from the power source. For stable operation over the full temperature range, with load
currents up to 120mA, a minimum of 1µF is recommended.
Dynamic Current Feedback
The G920 is designed to work with both low and high
ESR output capacitors. Since a PMOS transistor is
used as the output transistor, an output capacitor
greater than 1 µF is needed to stabilize the feedback
loop of the regulator. Due to the large value of the output capacitor, the dominant pole is the pole caused by
the output node. The pole cause by the error amplifier’s output node is the second pole. With a high ESR
output capacitor, the zero caused by the ESR is typically near the second pole so that the second pole is
cancelled by the zero, and the loop is stable. However,
when the output capacitor has a low ESR, the zero will
be much larger than the second pole. When the zero
is near or larger than the unity-gain frequency, it can
no longer cancel the phase shift caused by the second
pole, and the loop becomes unstable. The G920 uses
dynamic current feedback to stabilize the loop. The
output impedence of the error amplifier is reduced
when the output current increases. Thus, the second
pole is pushed outward in accordance with the output
current so that the second pole can be cancelled by
the ESR’s zero to maintain regulator stability.
Power-Supply Rejection and Operation from
Sources Other than Batteries
The G920 is designed to deliver low dropout voltages
and low quiescent currents in battery powered systems. Power-supply rejection is 53dB at low frequencies as the frequency increases above 20kHz, the
output capacitor is the major contributor to the rejection of power-supply noise.
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 G920 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.
Over Temperature Protection
To prevent abnormal temperature from occurring, the
G920 has a built-in temperature monitoring circuit.
When it detects the temperature is above 170oC, the
output transistor is turned off. When the IC is cooled
down to below 150oC, the output is turned on again. In
this way, the G920 will be protected against abnormal
junction temperature during operation.
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 G920 use a P-channel MOSFET pass transistor, their dropout voltage is a function of RDS(ON)
multiplied by the load current.
Shutdown Mode
When the EN pin is connected a logic low voltage, the
G920 enters shutdown mode. All the analog circuits
are turned off completely, which reduces the current
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver 0.0 Preliminary
Mar 27, 2001
6
G920
Global Mixed-mode Technology Inc.
Package Information
C
E
H
L
D
θ
7 ° (4X)
A2
A
A1
y
e
B
Note:
1. Package body sizes exclude mold flash and gate burrs
2. Dimension L is measured in gage plane
3. Tolerance 0.10mm unless otherwise specified
4. Controlling dimension is millimeter converted inch dimensions are not necessarily exact.
SYMBOL
A
A1
A2
B
C
D
E
e
H
L
y
θ
MIN.
DIMENSION IN MM
NOM.
MAX.
MIN.
1.35
0.10
----0.33
0.19
4.80
3.80
----5.80
0.40
----0º
1.60
----1.45
----------------1.27
-----------------
1.75
0.25
----0.51
0.25
5.00
4.00
----6.20
1.27
0.10
8º
0.053
0.004
----0.013
0.007
0.189
0.150
----0.228
0.016
----0º
DIMENSION IN INCH
NOM.
0.063
----0.057
----------------0.050
-----------------
MAX.
0.069
0.010
----0.020
0.010
0.197
0.157
----0.244
0.050
0.004
8º
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver 0.0 Preliminary
Mar 27, 2001
7
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