Gamma GM1431CST23T Adjustable shunt regulator Datasheet

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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
Features
Description
The GM1431 is a three terminal adjustable shunt regulator
Sink Current Capability 1 mA to 100mA
with thermal stability guaranteed over temperature. Output
Low dynamic output impedance, 0.2W typ.
voltage can be adjusted to any value between 2.5V (Vref)
0.5%, 1% or 2% reference voltage tolerance
and 36V by using two external resistors. The GM1431 has
Alternate for TL431, TL431, LM431 & AS431
a typical dynamic output impedance of 0.2W. Active output
Temperature range 0°C to+ 70 °C
circuitry provides a very unique turn on characteristic, making the GM1431
an excellent tum on replacement for
zener diodes in many applications such as onboard regula-
Available in SOT-23, TO-92, SOT-89 and
SOP- 8 packages
tion and adjustable power supplies. The GM1431 is an
ideal voltage reference for 3.0 to 3.3V switching power supplies.
The GM1431 shunt regulator is available with 3 voltage tolerances, 0.5%, 1.0% and 2.0% over TA= 0°C to + 70°C,
and four package options (SOT-23, TO-92, SOT-89 and
SOP-8). Whatever your application is, the GM1431 offers
the optimum combination of performance, reliability, and
economy.
Application
Switching power supplies
Battery-operated computers
Linear regulators
Computer disk drives
Adjustable supplies
Instrumentation
LOGIC SYMBOL
BLOCK DIAGRAM (POSITIVE LOGIC)
REFERENCE
REFERENCE
GM1431 V0.11
CATHODE
+
_
ANODE
CATHODE
V ref
ANODE
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1
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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
MARKING INFORMATION & PIN CONFIGURATIONS (TOP VIEW)
TO- 92
SOP- 8
SOT-23
ANODE
REF
Anode
GM
1431G
AYWW
3
1 2
GM1431G
AYWW
GM1431G
AYWW
2
1
Cathode
REF
ANODE
NC
8 7 6 5
XXXYW
1. REF
2. Anode
3. Cathode
SOT - 89
1 2 3 4
CATHODE
ANODE
3
REF 1
NC
ANODE
2
3 CATHODE
ANODE
XXX = Marking Code
G** = Grade
A
= Assembly Location
Y
= Year
WW, W= Weekly
ORDERING INFORMATION
GM1431
Ordering Number
2
Precision
Device code
Grade
Package
Shipping
GM1431AT92B
0.5%
A
TO-92
1,000 Units/ ESD Bag
GM1431AT92RL
0.5%
A
TO-92
2,000 Units/ Ammo Pack(Tape)
GM1431AST23R
0.5%
SOT-23
3,000 Units / Tape &Reel
GM1431AS8T
0.5%
A
SOP-8
100 Units / Tube
GM1431AS8R
0.5%
A
SOP-8
2,500 Units / Tape & Reel
GM1431AST89R
0.5%
A
SOT-89
1,000 Units / Tape & Reel
GM1431BT92B
1%
B
TO-92
1,000 Units/ ESD Bag
GM1431BT92RL
1%
B
TO-92
2,000 Units/ Ammo Pack(Tape)
GM1431BST23R
1%
SOT-23
3,000 Units / Tape &Reel
GM1431BS8T
1%
B
SOP-8
100 Units / Tube
GM1431BS8R
1%
B
SOP-8
2,500 Units / Tape & Reel
GM1431BST89R
1%
B
SOT-89
1,000 Units / Tape & Reel
GM1431CT92B
2%
C
TO-92
1,000 Units/ ESD Bag
GM1431CT92RL
2%
C
TO-92
2,000 Units/ Ammo Pack(Tape)
GM1431CST23R
2%
SOT-23
3,000 Units / Tape &Reel
GM1431CS8T
2%
C
SOP-8
100 Units / Tube
GM1431CS8R
2%
C
SOP-8
2,500 Units / Tape & Reel
GM1431CST89R
2%
C
SOT-89
1,000 Units / Tape & Reel
NAA
NAB
NAC
* For detail Ordering Number identification, please see last page.
**Grade A: indicates Precision of 0.5%, B: indicates Precision of 1%, C: indicates Precision of 2%
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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
EQUIVALENT SCHEMATIC
CATHODE
800W
800W
20pF
REF
150W
3.28KW
4KW
10kW
2.4KW
20pF
7.2KW
1kW
800W
ANODE
GM1431
* All component values are nominal.
Pin numbers shown are for the D package.
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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
ABSOLUTE MAXIMUM RATINGS (over free-air temperature range except as noted)
SYMBOL
VALUE
UNIT
VKA
37
V
Continuous cathode current
IK
-100 to 150
mA
Reference input current range
Iref
-50µA to 10mA
mA
Power dissipation at TA = 25°C
SOT-23
SOP-8
TO-92
SOT-89
PD
Package thermal impedance (2, 3)
SOT-23
TO-92
SOP-8
SOT-89
qJA
336
132
163
132
Operating ambient temperature range
TA
0 to 70
°C
TLEAD
TJ
260
°C
PARAMETER
Cathode Voltage (1)
Lead temperature (soldering) 10 seconds
0.23
0.60
0.78
0.80
W
°C/W
These are stress ratings only. Functional operation of the device at these or any conditions beyond the "recommended
operating conditions" is not implied. Exposure to absolute maximum rated conditions may affect device reliability.
NOTES:
1. Voltage values are with respect to the anode except as noted.
2. Maximum power dissipation is a function of TJ(max), qJA and TA. Maximum allowable power dissipation at any allowable ambient temperature is
PD = (TJ(max) 3. Package thermal impedance is calculated per JESD 51.
RECOMMENDED OPERATING CONDITIONS
SYMBOL
MINIMUM
MAXIMUM
UNIT
Cathode Voltage
VKA
Vref
36
V
Cathode Current
IK
1.0
100
mA
GM1431
PARAMETER
4
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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted)
GM1431A (0.5%)
PARAMETER
CONDITION
Reference Input Voltage
Vref
Vref temp deviation
Vdev
Ratio of change in Vref
to change in VKA
DVref
DVKA
Reference input current
Iref
VKA = Vref, IK = 10 mA, TA = 25°C (1)
VKA=Vref,IK=10 mA,TA= 0 to 70°C(1)
MIN
TYP
MAX
UNIT
2.487
2.500
2.512
V
4
17
mV
VKA = Vref, IK = 10 mA (1), TA = full range
IK = 10mA
DVKA = 10V to Vref
-2.7
-2.0
DVKA = 36V to 10V
IK = 10mA, R1 = 10KW, R2 =
(2)
Deviation of reference
input current over full
temperature range
I = 10mA, R1 = 10KW, R2 =
Iref(dev) K
TA = full range
(2)
Minimum operating
current
IK(min) VKA = Vref (1)
Off-state cathode
current
IK(off)
Dynamic impedance
| ZKA | f 1kHz,VKA=Vref, IK=100mA to 100mA (1)
VKA = 36V, Vref = 0V
-1.0
-0.4
mV/V
1.3
4.0
mA
0.4
1.2
mA
0.4
1.0
mA
0.1
1
mA
0.2
0.50
W
MIN
TYP
MAX
UNIT
2.474
2.500
2.525
V
4
17
mV
(3)
VKA = 16V, Vref = 0V (3)
GM1431B (1.0%)
PARAMETER
CONDITION
Reference Input Voltage
Vref
Vref temp deviation
Vdev
Ratio of change in Vref
to change in VKA
DVref
DVKA
Reference input current
Iref
VKA = Vref, IK = 10 mA, TA = 25°C
(1)
VKA=Vref,IK=10 mA,TA= 0 to 70°C(1)
VKA = Vref, IK = 10 mA (1), TA = full range
IK = 10mA
DVKA = 10V to Vref
DVKA = 36V to 10V
IK = 10mA, R1 = 10KW, R2 =
(2)
Deviation of reference
input current over full
temperature range
I = 10mA, R1 = 10KW, R2 =
Iref(dev) K
TA = full range
(2)
Minimum operating
current
IK(min) VKA = Vref (1)
Off-state cathode
current
IK(off)
Dynamic impedance
| ZKA | f 1kHz,VKA=Vref, IK=100mA to 100mA (1)
VKA = 36V, Vref = 0V (3)
VKA = 16V, Vref = 0V (3)
-2.7
-2.0
-1.0
-0.4
mV/V
1.3
4.0
mA
0.4
1.2
mA
0.4
1.0
mA
0.1
1
mA
0.2
0.50
W
GM1431
NOTES:
(1) See test circuit 1 on page 5.
(2) See test circuit 2 on page 5.
(3) See test circuit 3 on page 5.
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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted)
GM1431C (2.0%)
PARAMETER
CONDITION
Reference Input Voltage
Vref
Vref temp deviation
Vdev
Ratio of change in Vref
to change in VKA
DVref
DVKA
Reference input current
Iref
VKA = Vref, IK = 10 mA, TA = 25°C (1)
VKA=Vref,IK=10 mA,TA= 0 to 70°C(1)
MIN
TYP
MAX
UNIT
2.45
2.500
2.55
V
4
17
mV
VKA = Vref, IK = 10 mA (1), TA = full range
DVKA = 10V to Vref
IK = 10mA
DVKA = 36V to 10V
IK = 10mA, R1 = 10KW, R2 =
(2)
Deviation of reference
input current over full
temperature range
I = 10mA, R1 = 10KW, R2 =
Iref(dev) K
TA = full range
(2)
Minimum operating
current
IK(min) VKA = Vref (1)
Off-state cathode
current
IK(off)
Dynamic impedance
| ZKA | f 1kHz,VKA=Vref, IK=100mA to 100mA (1)
-2.7
-2.0
-1.0
-0.4
mV/V
1.3
4.0
mA
0.4
1.2
mA
0.4
1.0
mA
0.1
1
mA
0.2
0.50
W
(3)
VKA = 36V, Vref = 0V
VKA = 16V, Vref = 0V
(3)
NOTES:
(1) See test circuit 1.
(2) See test circuit 2.
(3) See test circuit 3.
TEST CIRCUITS
VIN
VKA
VIN
VKA
lref
lk
VIN
VKA
lk(off)
R1
V ref
R2
lref
Vref
GM1431
Vref
6
Test Circuit 1
V KA = V ref
Test Circuit 2
V KA > V ref
Test Circuit 3
Off-State
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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
TYPICAL APPLICATIONS
GM1431A, GM1431B
Vin
Vout
Vout
Vin
R1
R1
R2
R2
R1
Vout=( 1+ R2 ) Vref
Vout=( 1+
Figure 1. Shunt Regulator
Vin
R1
) Vref
R2
Figure 2. High Current Shunt Regulator
Vout
Vin
GM 7805
In
Out
Common
Vout
R1
R1
R2
R2
Vout=(1+
R1
)Vref
R2
Vout=(1+
Vout(min) = Vref+ 5.0V
Vout(min) = Vref+ Vbe
Figure 3. Output Control for a Three
Terminal Fixed Regulator
RCL
Vin
Iout
R1
) Vref
R2
2.0V
Figure 4. Series Pass Regulator
Vin
Isink
Vout
V
Isink= ref
RS
Vref
RS
RCL
Figure 6. Constant Current Sink
Figure 5. Constant Current Source
Vout
Vin
Vout
Vin
R1
R1
R2
R2
Vout(trip)=(1 +
R1
) Vref
R2
Figure 7. TRIAC Crowbar
Vout(trip)=(1 +
R1
) Vref
R2
Figure 8. SCR Crowbar
GM1431
Iout=
7
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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
Typical Performance Characteristics
150
Cathode current (mA)
200
800
Cathode current (mA)
1000
600
400
200
0
-200
50
0
-50
-100
-400
-1 -0.5
Iref, REFERENCE INPUT CURRENT (mA)
100
0
0.5
1
1.5
2
2.5
-150
-2
3
-1
0
1
2
3
Cathode Voltage (V)
Cathode Voltage (V)
Figure 9. Cathode Current vs.
Cathode Voltage
Figure 10. Cathode Current vs.
Cathode Voltage
2.5
0.6
0.5
Impedance (W)
2
0.4
0.3
0.2
1.5
1
0.5
0.1
0
0
0
20
40
60
80
0
100K 200K 300K 400K 500K
600K
Frequency (Hz)
T A , AMBIENT TEMPERATURE (°C)
Avol, OPEN LOOP VOLTAGE GAIN (dB)
Vref, REFERENCE INPUT VOLTAGE (V)
2.5
2.498
2.496
2.494
2.492
2.49
2.488
2.486
0
20
40
60
80
1k
10k
100k
1M
f, FREQUENCY (HZ)
Figure 13. Reference Input Voltage versus
Figure 14. Open-Loop Voltage Gain
vs. Frequency
IK- Cathode Current (mA)
GM1431
0°
I KA =10mA
36°
T A =25°C
72°
108°
144°
180°
T A , AMBIENT TEMPERATURE (°C)
Ambient Temperature
8
80
70
60
50
40
30
20
10
0
-10
-20
100
100
A: VKA = VREF
90
B: VKA = 5V
80
C: VKA = 10V
70
D: VKA = 15V
60
50
Stability A
40
Region
30
20
TA = 25°
10
B
0 0
1
2
3
4
5
6
7
10 10 10 10 10 10 10 10
CL-Load Capacitance(pF)
Figure 15. Stability Boundary Conditions
(No Oscillation at VKA=10V and VKA=15V)
Phase Shift
Figure 12. Dynamic Impedance
Frequency
Figure 11. Reference Input Current versus
Ambient Temperature
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Power Management
GM1431
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MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
Design Guide for AC-DCSMPS (Switching Mode Power Supply)
Use of Shunt Regulator in Transformer Secondary Side Control
This example is applicable to both forward transformers and flyback transformers. A shunt regulator is used on the secondary
side as an error amplifier, and feedback to the primary side is provided via a photocoupler.
Transformer
R1
SBD
R3
GM384X
GM38C4X
(+)
Output
IF
VF
Phototransistor
Photocoupler
Light
emitting diode
VO
R2
IB
(-)
Vref
VK
R5
C1
R4
REF
GM1431
GND
Figure 16. Typical Shunt Regulator/ Error Amplifier
Determination of External Costants for the Shunt Regulator
R1 =
VO - VF - VK
I F +I B
, R2 =
VF
IB
VK Is the GM1431 operating voltage, and is set at
around 3V, taking into account a margin for
fluctuation. R2 is the current shunt resistance for the
light emitting diode, in which a bias current IB of
around 1/5 IF flows.
Next, the output voltage can be determined by R3
and R4, and the following formula is obtained:
VO =
R3 +R4
X V ref , V erf =2 .5 V Typ
R4
The absolute values of R3 and R4 are determined by
the GM1431 reference input current Iref and the AC
characteristics described in the next section. The Iref
value is around 1.3µA Typ.
GM1431
Dc characteristic determination: In figure 16, R1
and R2 are protection resistor for the light emitting
diode in the photocoupler, and R2 is a bypass
resistor to feed IK Minimum, and these are
determined as shown below. The photocoupler
specification should be obtained separately from the
manufacturer. Using the parameters in figure 16, the
following formulas are obtained:
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Power Management
GM1431
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MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
AC Characteristic Determination:
This refers to the determination of the gain frequency characteristic of the shunt regulator as an error amplifier.
Taking the configuration in figure 16, the error amplifier characteristic is as shown in figure 17.
G1
Gain G (dB)
* fosc: PWM switching frequency
G2
When R5= 0
When R5= 0
f1
fAC
f2
fosc Frequency f (Hz)
Figure 17. GM1431 Error Amplification Characteristic
In Figure 17, the following formulas are obtained:
Gain
G1 = G0 50 dB to 60 dB (determined by shunt regulator)
G2 =
R5
R3
Corner frequencies
f1 = 1/(2p C1 G0 R3)
f2 = 1/(2p C1 R5)
G0 is the shunt regulator open-loop gain; this is given by the reciprocal of the reference voltage fluctuation
DVref/DVKA, and is approximately 50 dB.
Practical Example
Consider the example of a photocoupler, with an internal light emitting diode VF = 1.05 V and IF = 2.5 mA,
power supply output voltage V2 = 5 V, and bias resistance R2 current of approximately 1/5 IF at 0.5 mA. If
the shunt regulator VK = 3 V, the following values are found.
R1=
5V - 1.05V - 3V
=316W
2.5mA + 0.54mA
R2=
1.05V
=2.1 kW
0.54mA
Next, assume that R3 = R4 = 10 kW. This gives a 5 V output. If R5 = 3.3 kW and C1 = 0.022 µF, the
following values are found.
GM1431
G2 = 3.3 kW / 10 kW = 0.33 times (–10 dB)
f1 = 1 / (2 x p x 0.022 µF x 316 x 10 kW) = 2.3 (Hz)
f2 = 1 / (2 x p x 0.022 µF x 3.3 kW) = 2.2 (kHz)
10
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Power Management
GM1431
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MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
SOT-89 PACKAGE OUTLINE DIMENSIONS
4.50 ± 0.05
1.650 REF
Units: mm
Pad Layout
1.50 ± 0.05
1.400 REF
2
R 0.13~4X
NO DRAFT~2
R 0.13~3X
3
4.20 ± 0.05
2.5 ± 0.05
45°
6°
R 0.1 MAX
1.00 ± 0.07
0.7
0.46 ± 0.025
0.38 ± 0.01
1.50
1.5
1.50
3.00 ± 0.025
1.5
6°~2X
1
R 0.13~2X
R 0.13~2X
Unit: mm
6°~2X
SOT-23 PACKAGE OUTLINE DIMENSIONS
2.90 ± 0.1
0.13
0.4 ± 0.1
Pad Layout
0~0.1
0.031
1.5 ± 0.05
2.8 ± 0.1
0.8
0.035
0.9
0.65 ± 0.05
0.079
2.0
0.95 ± 0.038
0.8 ± 0.05
1.9 ± 0.05
1.10 ± 0.1
Unit: mm
0.037
0.037
0.95
0.95
Inches
( mm )
GM1431
5°
11
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Power Management
GM1431
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MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
SOP-8 PACKAGE OUTLINE DIMENSIONS
0.008 +0.0018
-0.0005
0.200
+0.05
-0.01
0 ° ~ 8°
0.028
0.710
+0.013
-0.022
Pad Layout
0.060
+0.33
-0.56
1.52
0.236 ± 0.008
5.990
+0.21
-0.20
0.154
+0.003
-0.004
0.275
0.155
7.0
4.0
PIN INDENT
3.91 ± 0.1
0.024
0.050
0.6
1.270
Inches
( mm )
0.191
+0.002
-0.004
4.850
+0.05
-0.10
0.057 NOM
1.450 NOM
0.063 ± 0.005
1.600 ± 0.130
( Inches )
mm
0.007 ± 0.003
0.175 ± 0.075
0.050 NOM
1.270 NOM
0.016
+0.004
-0.003
0.410
+0.10
-0.08
TO-92 PACKAGE OUTLINE DIMENSIONS
4.6 ± 0.1
3.6 ± 0.15
2°
2°
4.6 ± 0.1
2.3
2°
1.45 ± 0.1
2°
3 - 0.46
GM1431
14.5 ± 0.5
12
0.38 ± 0.015
1.27 1.27
Unit: mm
3.6 ± 0.15
1.3 ± 0.1
5°
5°
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Power Management
GM1431
A
MICROELECTRONICS
ADJUSTABLE SHUNT REGULATOR
ORDERING NUMBER
GM 1431 A T92 B
Shipping
B : ESD Bag
RL: Ammo Pack
R: Tape & Reel
T: Tube
Gamma Micro.
Circuit Type
(Tape)
Package
T92: TO-92
ST23: SOT-23
S8: SOP-8
ST89: SOT-89
GM1431
Voltage Tolerance
A: 0.5%
B: 1.0%
C: 2.0%
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ADJUSTABLE SHUNT REGULATOR
GM1431
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MICROELECTRONICS
Power Management
GM1431
14 12