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TL431X

Precision Programmable Reference

The TL431X is a precision programmable reference from Texas Instruments. View the full TL431X datasheet below including electrical characteristics, absolute maximum ratings.

Manufacturer

Texas Instruments

Category

Precision Programmable Reference

Overview

Part: TL431, TL432 from Texas Instruments

Type: Precision Programmable Reference

Description: Three-terminal adjustable shunt regulators with output voltage adjustable from Vref (approximately 2.5V) to 36V, sink-current capability from 1mA to 100mA, and operation from -40°C to 125°C.

Operating Conditions:

  • Cathode voltage: Vref to 36V
  • Operating temperature: -40 to 125 °C (for TL43xxQ devices)
  • Continuous cathode current: 1 to 100 mA

Absolute Maximum Ratings:

  • Max cathode voltage: 37 V
  • Max continuous cathode current: 150 mA
  • Max junction/storage temperature: 150 °C

Key Specs:

  • Reference Voltage (Vref): 2440 mV to 2550 mV (Typ 2495 mV) at VKA = Vref, IKA = 10mA
  • Reference voltage tolerance: 0.5% (B grade), 1% (A grade), 2% (Standard grade) at 25°C
  • Dynamic Impedance (|ZKA|): 0.2 Ω (Typ) to 0.5 Ω (Max) at VKA = Vref, f ≤ 1kHz, IKA = 1mA to 100mA
  • Minimum cathode current for regulation (Imin): 0.4 mA (Typ) to 1 mA (Max) at VKA = Vref
  • Reference Input Current (Iref): 2 μA (Typ) to 4 μA (Max) at IKA = 10mA
  • Off-state cathode current (Ioff): 0.1 μA (Typ) to 1 μA (Max) at VKA = 36V, Vref = 0
  • Ratio of change in reference voltage to the change in cathode voltage (ΔVref / ΔVKA): -1.4 mV/V (Typ) to -2.7 mV/V (Max) for ΔVKA = 10V-Vref

Features:

  • Reference voltage tolerance at 25°C
  • -0.5% (B grade)
  • -1% (A grade)
  • -2% (Standard grade)
  • Adjustable output voltage: Vref to 36V
  • Operation from -40°C to 125°C
  • Typical temperature drift (TL43xB)
  • -6mV (C temp)
  • -14mV (I temp, Q temp)
  • Low Output Noise
  • 0.2Ω Typical output impedance
  • Sink-current capability: 1mA to 100mA

Applications:

  • Rack server power
  • Industrial AC/DC
  • AC inverter & VF drives
  • Servo drive control module
  • Notebook PC power adapter design

Package:

  • SOT-23-3
  • SOT-23-5
  • SOIC (8)
  • PDIP (8)
  • SOP (8)
  • PK (SOT-89)

Features

  • Reference voltage tolerance at 25°C
  • -0.5% (B grade)
  • -1% (A grade)
  • -2% (Standard grade)
  • Adjustable output voltage: V ref to 36V
  • Operation from -40°C to 125°C
  • Typical temperature drift (TL43xB)
  • -6mV (C temp)
  • -14mV (I temp, Q temp)
  • Low Output Noise
  • 0.2Ω Typical output impedance
  • Sink-current capability: 1mA to 100mA

Applications

Simplified Schematic

Pin Configuration

TL431, TL431A, TL431B . . . D (SOIC) PACKAGE (TOP VIEW)

NC - No internal connection

NC - No internal connection †

TL431, TL431A, TL431B . . . PK (SOT-89) PACKAGE (TOP VIEW)

Pin 2 is attached to Substrate and must be connected to ANODE or left open.

Table 5-1. Pin Functions

Table 5-1. Pin Functions

PINPINPINPINPINPINPINPINPINPINPIN
NAMETL431xTL431xTL431xTL431xTL431xTL431xTL431xTL432xTL432xTL432x
NAMEDBZDBVPKDP, PS PWLPDCKDBZDBVPK
CATHODE1331111241
REF2418833153
ANODE3522, 3, 6, 7626322

Table 5-1. Pin Functions

Electrical Characteristics

over recommended operating conditions, TA = 25°C (unless otherwise noted)

PARAMETERPARAMETERTEST CIRCUITTEST CONDITIONSTEST CONDITIONSMINTYPMAXUNIT
V refReference VoltageSee Figure 7-1V KA = V ref , I KA = 10mAV KA = V ref , I KA = 10mA244024952550mV
V I(dev)Deviation of reference input voltage over full temperature range (1)See Figure 7-1V KA = V ref , I KA = 10mASOT23-3 and TL432 devices616mV
V I(dev)Deviation of reference input voltage over full temperature range (1)See Figure 7-1V KA = V ref , I KA = 10mAAll other devices425mV
ΔV ref / ΔV KARatio of change in reference voltage to the change in cathode voltageSee Figure 7-2I KA = 10mAΔV KA = 10V- V ref-1.4-2.7mV/V
ΔV ref / ΔV KARatio of change in reference voltage to the change in cathode voltageSee Figure 7-2I KA = 10mAΔV KA = 36V- 10V-1-2mV/V
I refReference Input CurrentSee Figure 7-2I KA = 10mA, R1 = 10kΩ, R2 = ∞I KA = 10mA, R1 = 10kΩ, R2 = ∞24μA
I I(dev)Deviation of reference input current over full temperature range (1)See Figure 7-2I KA = 10mA, R1 = 10kΩ, R2 = ∞I KA = 10mA, R1 = 10kΩ, R2 = ∞0.41.2μA
I minMinimum cathode current for regulationSee Figure 7-1V KA = V refV KA = V ref0.41mA
I offOff-state cathode currentSee Figure 7-3V KA = 36V, V ref = 0V KA = 36V, V ref = 00.11μA
\Z KA \Dynamic Impedance (2)See Figure 7-1V KA = V ref , f ≤ 1kHz, I KA = 1mA to 100mAV KA = V ref , f ≤ 1kHz, I KA = 1mA to 100mA0.2

Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted) (1)

MINMAXUNIT
V KACathode Voltage (2)37V
I KAContinuos Cathode Current Range-100150mA
I I(ref)Reference Input Current-0.0510mA
T JOperating Junction Temperature Range150°C
T stgStorage Temperature Range-65150°C

Recommended Operating Conditions

See (1)

MINMAXUNIT
V KACathode VoltageCathode VoltageV ref36V
I KAContinuous Cathode Current RangeContinuous Cathode Current Range1100mA
T AOperatingTL43xxC070°C
OperatingTL43xxI-4085°C
OperatingTL43xxQ-40125°C

Thermal Information

TL43xxTL43xxTL43xxTL43xxTL43xxTL43xxTL43xxTL43xxTL43xx
THERMAL METRIC (1)THERMAL METRIC (1)PPWDPSDCKDBVDBZLPPK
8 PINS8 PINS8 PINS8 PINS6 PINS5 PINS3 PINS3 PINS3 PINS
R θJAJunction-to-ambient thermal resistance85149979525920620614052
R θJC(top)Junction-to-case (top) thermal resistance576539468713176559

Typical Application

As this device has many applications and setups, there are many situations that this datasheet can not characterize in detail. The linked application notes will help the designer make the best choices when using this part.

Application note Understanding Stability Boundary Conditions Charts in TL431, TL432 Data Sheet (SLVA482) will provide a deeper understanding of this devices stability characteristics and aid the user in making the right choices when choosing a load capacitor. Application note Setting the Shunt Voltage on an Adjustable Shunt Regulator (SLVA445) assists designers in setting the shunt voltage to achieve optimum accuracy for this device.

Related Variants

The following components are covered by the same datasheet.

Part NumberManufacturerPackage
TL431ACDRTexas Instruments—
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