L432NB [ETC]

1.24V Low-Voltage Adjustable Precision Shunt Regulator; 1.24V低电压可调精密并联稳压器


型号：	L432NB
厂家：	ETC
描述：	1.24V Low-Voltage Adjustable Precision Shunt Regulator 1.24V低电压可调精密并联稳压器稳压器
文件：	总11页 (文件大小：284K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

GENERAL DESCRIPTION

FEATURES

The L432 is a three-terminal adjustable shunt

regulator utilizing an accurate 1.24V band gap

reference. The output voltage can be set to any

value between 1.24V (V_REF) to 18V with two

external resistors as shown in the typical

application circuit. The device exhibit a wide

operating current range of 0.2 to 100 mA with a

typical dynamic impedance of 0.25Ω. Active

output circuitry provides a very sharp turn-on

characteristic, making the L432 excellent re-

placements for low-voltage zener diodes in

many applications, including on-board regulat-

ion and adjustable power supplies.

z Internal amplifier with 100 mA capability

z Programmable output voltage to 18V

z 0.25Ω typical output impedance

z Pin to pin compatible with TLV431A,

TS431, SC431L & AS432

z Trimmed bandgap design 0.5% & 1.0%

with three package options

z Low output noise

APPLICATIONS

z Linear regulator controller

z Precision voltage reference

z Switching power supplies

z Battery operating equipment

z Instrumentation

When used with an opto-coupler, the L432 is

ideal voltage reference in isolated feedback

circuits for 3.3V switching-mode power supplies.

The L432 shunt regulator is available in two

voltage tolerances (0.5% & 1.0%) and three

package options (TO-92, SOT-23-3 and SO-8).

z PCs, Computer disk drives

SYMBOL & BLOCK DIAGRAM

Reference

Cathod

Cathode (K)

(R)

(K)

Reference (R)

1.24 Vref

Anode (A)

SYMBOL

FUNCTIONAL BLOCK DIAGRAM

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

ABSOLUTE MAXIMUM RATINGS

PARAMETER

VALUE

Cathode-Anode Reverse Breakdown Voltage - V_KA

Anode-Cathode Forward Current - I_AK

Operating Cathode Current - I_KA

Reference Input Current - I_REF

Storage Temperature Range - T_STG

Junction Temperature - T_J

Lead Temperature (Soldering, 10 Seconds) - T_L

Continuous Power at 25 °C - P_D

TO-92

20V

1 A

100 mA

1 mA

-65 to +150 °C

150 °C

300 °C

700 mW

650 mW

200 mW

SOIC-8

SOT-23

RECOMMENDED CONDITIONS

TYPICAL THERMAL RESISTANCES

Parameter

Cathode Voltage (V_KA) V_REFto 18V

Cathode Current (I_K) 10 mA

Rating

Package

TO-92

Typ. De-rating

160 °C/W 80 °^JC^C/W

6.3 mW/°C

5.7 mW/°C

1.7 mW/°C

SOIC-8 175 °C/W 45 °C/W

SOT-23 575 °C/W 150 °C/W

ELECTRICAL SPECIFICATIONS

(Ambient temperature must be derated base on power dissipation and package thermal characteristics. The conditions are: V_KA= V_REFand

I_K= 10 mA unless otherwise stated)

TEST

UNITS

MIN TYP MAX

PARAMETER

TEST CONDITIONS

CIRCUIT

T_A= 25 °C, L432 (0.5%) 1.234 1.240 1.246

T_A= 25 °C, L432 (1%) 1.228 1.240 1.252

Output Voltage - V_REF

µA

V_KA= V_REFto 15V

I_K= 1 to 100 mA

0 < T_J< 105 °C

3.9

Line Regulation - ∆V_REF

Load Regulation - ∆V_REF

Temperature Deviation - ∆V_REF

Reference Input Current - I_REF

Reference Input Current

Temperature Coefficient - ∆I_REF

Minimum Cathode Current

for Regulation - I_K(MIN)

2.3

0 < T_J< 105 °C

0.14 0.6

µA

0.2

Off State Leakage - I_K(MIN)

Dynamic impedance

V_REF= 0V, V_KA= 15V

VKA = Vref, f ≦ 1kHz

IK = 0.1 mA to 100 mA

500

0.25 0.4

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

TEST CIRCUITS

V_IN

V_KAV_IN

V_KA

I_K

I_{K (OFF)}

I_REF

V_REF

I_REF

- TEST CIRCUIT 1 -

- TEST CIRCUIT 2 -

- TEST CIRCUIT 3 -

(OFF STATE CURRENT)

V_REF

)

(V > V_REF

)

Applications Information – Stability

Selection of load capacitance when using

L432 as a shunt regulator

(or preferably, no)capacitance, or alter-

natively a high capacitance (such as 10uF)

will avoid this issue altogether. Since the

user will probably wish to have local

decoupling at the load anyway, the most

cost effective method is to use no

capacitance at all directly across the

device. PCB trace/via resistance and

inductance prevent the local load de-

coupling from causing the oscillation during

the transient start-up phase. Note : if the

L432 is located right at the load, so the

load decoupling capacitor is directly across

it, then this capacitor will have to be

≦ 100pF or ≧ 1uF.

When the L432 is used as a shunt regulator,

two options for selection of CL are

recommended for optimal stability:

1. No load capacitance across the device,

decouple at the load.

2. Large capacitance across the device,

optional decoupling at the load.

The reason for this is that L432 exhibits

instability with capacitances in the range of

1nF to 1uf (approx.) at light cathode currents

(up to 3mA typical). The device is less stable

the lower the cathode voltage has been set for.

Therefore while the device will be perfectly

stable operating at a cathode current of 10mA

with a 0.1uF capacitor across it, it will oscillate

transiently during start-up as the cathode

current passes through the instability region.

Selecting a very low

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

Small-Signal Gain and Phase Shift

VS. Frequency

Test Circuit for Small Signal Gain and Phase

OUT

232

15K

10uF

L432

8.25K

GND

Test Circuit for Stability

Stability Boundary Condition For Shunt Regulation

VS. Cathode Current and Load Capacitance

L432

Cathode Current

VS. Cathode Voltage

Cathode Current

VS. Cathode Voltage

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

Reference Voltage

VS. Junction Temperature

Reference Impedance

VS. Frequency

Reference Input Current

VS. Junction Temperature

Ratio of Delta Reference Voltage to Delta Cathode Voltage

VS. Junction Temperature

ΔVz = 16V to Vref

∞

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

Off-State Cathode Current

VS. Junction Temperature

Reference Impedance

VS. Junction Temperature

PIN CONFIGURATIONS

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

DEVICE SELECTION GUIDE

Device

Package

Marking

Tolerance

L432NB

L432M3B

SOT-23-3

2M3A

L432VB

SOIC-8

L432V

L432M5B

SOT-23-5

2M5A

TO-92

L432NA

APPLICATION CIRCUIT

P01N02LM or P3055L

Niko

Vin

Vout

Cin

5V or 12V

Cout

10uF

L431 or L432

Niko

Vout = (1 +

) Vref

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

TO-92 MECHANICAL DATA

Typ.

Dimension

Min.

Max.

5.207

5.334

15.5

0.533

1.397

4.191

1.270

Min.

Max.

2.667

0.533

4.445

4.318

12.7

0.356

1.143

3.175

0.762

2.413

0.356

2.540

1.27

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

SOT-23 (M3) MECHANICAL DATA

Typ.

0.15

Dimension

Min.

Typ.

0.95

2.80

1.60

2.90

1.10

Max.

Min.

0.10

0.37

Max.

0.25

2.60

1.40

2.70

1.00

0.00

0.35

3.00

1.80

3.10

1.30

0.10

0.5

0.4

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

SOIC-8 (D) MECHANICAL DATA

Typ.

Dimension

Min.

Max.

5.0

4.0

6.2

0.48

Min.

0.4

0.18

Max.

1.27

0.25

4.8

3.8

5.8

0.22

0.35

0°

8°

1.27

1.65

0.25

0.1

NOV-21-2001

1.24V Low-Voltage Adjustable

Precision Shunt Regulator

NIKO-SEM

L432

SOT-23 (M5) MECHANICAL DATA

Typ.

1.10

Typ.

Dimension

Min.

Max.

1.30

0.10

0.90

0.50

0.25

3.10

1.80

Min.

Max.

3.00

1.0

1.90(TYP)

2.80

0.00

0.70

0.35

0.10

2.70

1.40

2.60

0.37

0.80

0.40

0.15

2.90

1.60

NOV-21-2001

L432NB [ETC]

相关型号：

L432VB

L433

L433-0.25M

L433-019.44M

L433-025.0M

L433-155.52

L433-260.000M

L433-260.00M

L433-312.5M

L433-FREQ

L433C

L433EDT