Diodes ZHT431F01-7, ZHT431F01TA, ZHT431F02TA, ZHT431FMTA Schematic [ru]

A Product Line of

Diodes Incorporated

ZHT431

ADJUSTABLE PRECISION ZENER SHUNT REGULATOR

Description

The ZHT431 is a three terminal adjustable shunt regulator offering excellent temperature stability and output current handling capability up to 100mA. The device offers extended operating temperature range working from -55 to +125°C.

The output voltage may be set to any chosen voltage between 2.5 and 20 volts by selection of two external divider resistors.

The devices can be used as a replacement for zener diodes in many applications requiring an improvement in zener performance.

Features

•Surface mount SOT23 package

•0.5%, 1% and 2% tolerance

•Maximum temperature coefficient 67ppm/°C

•Temperature compensated for operation over the full temperature range

•Programmable output voltage

•50μA to 100mA current sink capability

•Low output noise

•Available in “Green” Molding Compound (See page 7)

•Wide temperature range -55 to +125°C

Pin Assignments

SOT23

VZ

GND

VREF

(Top View)

Applications

•Series and shunt regulator

•Voltage monitor

•Over voltage / under voltage protection

•Switch mode power supplies

Typical Application Circuit

ZHT431

1 of 8

November 2010

Document number: DS32157 Rev. 11 - 2

www.diodes.com

© Diodes Incorporated

A Product Line of

Diodes Incorporated

ZHT431

Absolute Maximum Ratings (Voltages to GND Unless Otherwise Stated)

Parameter

Rating

Unit

Cathode Voltage (VZ)

20

V

Cathode Current

150

mA

Operating Temperature

-55 to 125

°C

Storage Temperature

-55 to 150

°C

Power Dissipation

330

mW

(Tamb = 25°C, TJMAX = 150°C)

Recommended Operating Conditions

Parameter

Min

Max

Units

Cathode Voltage VREF

-

20

V

Cathode Current

0.05

100

mA

Electrical Characteristics

(Test conditions unless otherwise specified: Tamb = 25°C)

Symbol

Parameter

Values

Units

Conditions

Min.

Typ.

Max.

VREF

Reference Voltage

2%

2.45

2.50

2.55

IL=10mA (Fig.1),

1%

2.475

2.50

2.525

V

VZ=VREF

0.5%

2.4875

2.50

2.5125

VDEV

Deviation of reference input voltage

10

30

mV

IL=10mA, VZ=VREF

over temperature

Tamb=full range (Fig1)

VREF

Ratio of the change in reference voltage

-1.85

-2.7

mV/V

VZ from VREF to 10V

VZ

to the change in cathode voltage

IZ=10mA (Fig.2)

-1.0

-2.

mV/V

VZ from 10V to 20V

IZ=10mA (Fig.2)

IREF

Reference input current

0.12

1.0

µA

R1=10k, R2=O/C,

lL=10mA (Fig.2)

IREF

Deviation of reference input current

0.04

0.2

µA

R1=10k, R2=O/C,

IL=10mA Tamb=full range

over temperature

(Fig.2)

IZmin

Minimum cathode current for regulation

35

50

µA

VZ=VREF (Fig.1)

IZoff

Off-state current

0.1

µA

VZ=20V, VREF=0V(Fig.3)

RZ

Dynamic output impedance

0.75

V

VZ=VREF (Fig.1), f=0Hz,

IC=1mA to 100mA

Deviation of reference input voltage, VDEV, is defined as the maximum variation of the reference input voltage over the full temperature range.

The average temperature coefficient of the reference input voltage, VREF is defined as:

The dynamic output impedance, RZ, is defined as:

When the device is programmed with two external resistors, R1 and R2,

(fig 2) , the dynamic output impedance of the overall circuit, R’, is defined as:

ZHT431	2 of 8	November 2010
Document number: DS32157 Rev. 11 - 2	www.diodes.com	© Diodes Incorporated

Typical Operating Conditions

	170
	160
(nA)	150
Current	140
Reference	130
	120
	110
	100
	90
								-25				0			25			50			75			100			125
	-50
													Temperature (°C)
	40										I	R EF			vs. Temperature
(µA)	38
	36
Current	34
Cathode	32
Minimum	30
	28
	26
	24
								-25				0			25			50			75			100			125
	-50
													Temperature (°C)
											I				vs. Temperature
	2.502										Z MIN
	2.500
(V)	2.498
Voltage	2.496
Reference	2.494
	2.492
	2.490
	2.488
	2.486
								-25				0			25			50			75			100			125
	-50

Temperature (°C)

VREF vs. Temperature

A Product Line of

Diodes Incorporated

ZHT431

	0
																														I	= 10mA
(mV)																														Z
	-5
Voltage
Output	-10
Referencein	-15
Change	-20
	-250
			5										10											15							20
													Cathode Voltage (V)
						Change in V vs. Cathode Voltage
	100															REF
			VREF = VZ
Ω)	10																															1mA
(
Impedance
																																10mA
Dynamic	1.0
	0.1
	100									1K									10K								100K											1M

Frequency (Hz)

Dynamic Impedance vs. Frequency

	0.5
	0.4
(W)
Dissipation	0.3
	0.2
Power
	0.1
	0 0	25	50	75	100	125	150
			Ambient Temperature (°C)
			Power Dissipation Derating

ZHT431	3 of 8	November 2010
Document number: DS32157 Rev. 11 - 2	www.diodes.com	© Diodes Incorporated