GM1431BT92R中文资料

Description

The GM1431 is a three terminal adjustable shunt regulator with thermal stability guaranteed over temperature. Output voltage can be adjusted to any value between 2.5V (V ) ref and 36V by using two external resistors. The GM1431 has a typical dynamic output impedance of 0.2W . Active output circuitry provides a very unique turn on characteristic, mak-ing the GM1431 an excellent tum on replacement for zener diodes in many applications such as onboard regula-tion and adjustable power supplies. The GM1431 is an ideal voltage reference for 3.0 to 3.3V switching power sup-plies.

The GM1431 shunt regulator is available with 3 voltage tol-erances, 0.5%, 1.0% and 2.0% over T = 0°C to + 70°C, A 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.

LOGIC SYMBOL Application

Switching power supplies Linear regulators Adjustable supplies

Battery-operated computers Computer disk drives Instrumentation

BLOCK DIAGRAM (POSITIVE LOGIC)

CATHODE

REFERENCE

ANODE

CATHODE

Features

Sink Current Capability 1 mA to 100mA

Low dynamic output impedance, 0.2W typ. 0.5%, 1% or 2% reference voltage tolerance Temperature range 0°C to+ 70 °C Available in SOT -23, TO-92, SOT-89 and SOP- 8 packages

Alternate for TL431, TL431, LM431 & AS431G M 1431 V 0.11

https://www.sodocs.net/doc/149787268.html,

1

SOT - 89

TO- 92

SOP- 8

ANODE

1234

8765

ANODE

REF

ANODE NC

CATHODE ANODE

NC

ANODE

XXX = Marking Code G** = Grade

A = Assembly Location Y = Y ear WW, W= Weekly

GM 1431G AYWW

12

3

1. REF

2. Anode

3. Cathode

GM1431G AYWW

MARKING INFORMATION & PIN CONFIGURA TIONS (TOP VIEW)

G M 1431

2

SOT-23

XXXYW

Anode

Cathode

2

3

REF 1

ORDERING INFORMATION

* 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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EQUIVALENT SCHEMA TIC

* All component values are nominal.

Pin numbers shown are for the D package.

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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 T , q and T . Maximum allowable power dissipation at any allowable ambient temperature is J(max)JA A P = (T -

D J(max)3. Package thermal impedance is calculated per JESD 51.

RECOMMENDED OPERATING CONDITIONS

ABSOLUTE MAXIMUM RATINGS (over free-air temperature range except as noted)

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ELECTRICAL CHARACTERISTICS (T = 25°C unless otherwise noted)

A

GM1431B (1.0%)

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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ELECTRICAL CHARACTERISTICS (T = 25°C unless otherwise noted)A GM1431C (2.0%)NOTES:

(1) See test circuit 1.(2) See test circuit 2.(3) See test circuit 3.

A

A MICROELECTRONICS

GM1431

ADJUSTABLE SHUNT REGULATOR

TEST CIRCUITS

Test Circuit 1V

= V KA ref

Test Circuit 2V >

V KA ref

l (off)

k V IN

V KA Test Circuit 3Off-State

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TYPICAL APPLICATIONS

GM1431A, GM1431B

Figure 3. Output Control for a Three

Terminal Fixed Regulator

V = V + 5.0V

out(min) ref V =( + )out 1

R1

R2V ref V out

Series Pass Regulator

Figure 4. V out

Figure 1. Shunt Regulator

V V =( + )out 1R1

R2

V ref V out

Figure 2. High Current Shunt Regulator

V =( + )out 1

R1

R2

V ref V out

Constant Current Source

Figure 5.

V I =

out V ref R CL

out

Figure 6. Constant Current Sink

=sink V ref

R S

I Figure 7.

TRIAC Crowbar V out

V =( + )out(trip)1

R1

R2

V ref Figure 8.

SCR Crowbar

V =( + )out(trip)1

V ref R1

V out

V =( + )out 1

R1

V ref V = V + V 2.0V

out(min)ref be

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Typical Performance Characteristics

Cathode Voltage (V)

-1 -0.5 0 0.5 1 1.5 2 2.5 3

10008006004002000-200

-400

C a t h o d e c u r r e n t (m A ) Figure 9. Cathode Current vs.

Cathode Voltage

-2 -1 0 1 2 3

200150100500-50-100

-150

Cathode Voltage (V)

C a t h o d e c u r r e n t (m A )

Figure 10. Cathode Current vs.

Cathode Voltage

0 20 40 60 80

0.60.50.40.30.20.1

T , AMBIENT TEMPERATURE (°C)

A I , R E F E R E N C E I N P U T C U R R E N T (m A )

r e f Figure 11. Reference Input Current versus

Ambient Temperature

0 100K 200K 300K 400K 500K 600K

2.52

1.5

10.50

Frequency (Hz)

I m p e d a n c e (W )

Figure 12. Dynamic Impedance

Frequency

0 20 40 60 80

2.5

2.4982.4962.4942.4922.492.488

2.486

T , AMBIENT TEMPERATURE (°C)

A V , R E F E R E N C E I N P U T V O L T A G E (V )

r e f Figure 13. Reference Input Voltage versus

Ambient Temperature

100 1M 1k 10k 100k

Figure 14. Open-Loop Voltage Gain

vs. Frequency

A , O P E N L O O P V O L T A G E G A I N (d

B )

v o l f, FREQUENCY (HZ)

P h a s e S h i f t

10 1010 10 10 10 1010

I - C a t h o d e C u r r e n t (m A )

K C -Load Capacitance(pF)

L Figure 15. Stability Boundary Conditions

(No Oscillation at V =10V and V =15V)

KA KA

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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.

Dc characteristic determination: In figure 16, R 1and R are protection resistor for the light emitting 2diode in the photocoupler, and R is a bypass

2resistor to feed I Minimum, and these are K 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:

V Is the GM1431 operating voltage, and is set at

K around 3V, taking into account a margin for fluctuation. R is the current shunt resistance for the 2light emitting diode, in which a bias current I of B around 1/5 I

flows.

F Next, the output voltage can be determined by R 3and R , and the following formula is obtained:4The absolute values of R and R are determined by

34the GM1431 reference input current I and the AC

ref characteristics described in the next section. The I ref

value is around 1.3μA T yp. Determination of External Costants for the Shunt Regulator

R1 = , R2 =

V - V - V O F K I

+I F B V

F I

B

V = X V , V =2.5V Typ O ref erf R3 +R4R4

Figure 16. Typical Shunt Regulator/ Error Amplifier

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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.

AC Characteristic Determination:

Figure 17. GM1431 Error Amplification Characteristic

= 0

5= 05In Figure 17, the following formulas are obtained:

Gain

G = G 50 dB to 60 dB (determined by shunt regulator)

10

G =

2Corner frequencies

f = 1/(2p C G R )1103f = 1/(2p C R )

2 15

G is the shunt regulator open-loop gain; this is given by the reciprocal of the reference voltage fluctuation 0D Vref/D V , and is approximately 50 dB.

KA R 5R 3

Practical Example

Consider the example of a photocoupler, with an internal light emitting diode V = 1.05 V and I = 2.5 mA,F F power supply output voltage V = 5 V, and bias resistance R current of approximately 1/5 I at 0.5 mA. If 22F the shunt regulator V = 3 V, the following values are found.

K Next, assume that R = R = 10 k W . This gives a 5 V output. If R = 3.3 k W and C = 0.022 μF, the 3451following values are found.

G = 3.3 k W / 10 k W = 0.33 times (–10 dB)

2 f = 1 / (2 x p x 0.022 μF x 316 x 10 k W ) = 2.

3 (Hz)1 f = 1 / (2 x p x 0.022 μF x 3.3 k W ) = 2.2 (kHz)

2R = =316W

15V - 1.05V - 3V

2.5mA + 0.54mA R = =2.1 k W

2 1.05V

0.54mA

osc

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SOT-89 PACKAGE OUTLINE DIMENSIONS

Unit: mm

SOT-23 P ACKAGE OUTLINE DIMENSIONS

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TO-92 PACKAGE OUTLINE DIMENSIONS

Unit: mm

SOP-8 PACKAGE OUTLINE DIMENSIONS

0.050 NOM 1.270 NOM

-0.003

+0.10-0.08

0.410

+0.002-0.004

0.191 +0.05

Inches mm

( )

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ORDERING NUMBER

G M

1431

12

A

A MICROELECTRONICS

GM1431

ADJUSTABLE SHUNT REGULATOR

Power Management

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