TL431ACDR

Part: TL431ACDR (TL431A, C temp grade, SOIC-8) — Texas Instruments

Type: Precision Programmable Shunt Reference (Adjustable Shunt Regulator)

Description: Three-terminal adjustable shunt regulator with a 1% initial tolerance (A grade), output adjustable from Vref (about 2.5 V) to 36 V, 1 mA to 100 mA sink current, and 0.2 Ω typical dynamic impedance.

Operating Conditions:

• Cathode voltage: Vref to 36 V
• Operating temperature: 0 to 70 °C (TL431AC, C grade; the family covers -40 to 85 °C for I grade and -40 to 125 °C for Q grade)
• Continuous cathode current: 1 to 100 mA

Absolute Maximum Ratings:

• Cathode voltage (VKA): 37 V
• Continuous cathode current: -100 to 150 mA
• Reference input current: -0.05 to 10 mA
• Operating junction temperature: 150 °C
• Storage temperature: -65 to 150 °C

Key Specs:

• Reference voltage (TL431AC, VKA = Vref, IKA = 10 mA, TA = 25 °C): 2470 / 2495 / 2520 mV (min/typ/max)
• Reference voltage deviation over full temperature range: 4 mV typ, 25 mV max (all other devices, including SOIC); 6 mV typ, 16 mV max (SOT23-3 and TL432 devices)
• ΔVref/ΔVKA (IKA = 10 mA): -1.4 mV/V typ, -2.7 mV/V max (ΔVKA = 10 V − Vref); -1 mV/V typ, -2 mV/V max (ΔVKA = 36 V − 10 V)
• Reference input current (IKA = 10 mA, R1 = 10 kΩ, R2 = ∞): 2 μA typ, 4 μA max
• Reference input current deviation over temperature: 0.8 μA typ, 1.2 μA max
• Minimum cathode current for regulation (VKA = Vref): 0.4 mA typ, 0.6 mA max
• Off-state cathode current (VKA = 36 V, Vref = 0): 0.1 μA typ, 0.5 μA max
• Dynamic impedance (VKA = Vref, f ≤ 1 kHz, IKA = 1 to 100 mA): 0.2 Ω typ, 0.5 Ω max

Features:

• Reference voltage tolerance at 25 °C: 0.5% (B grade), 1% (A grade), 2% (standard grade)
• Adjustable output voltage from Vref to 36 V
• Sink-current capability of 1 mA to 100 mA
• Low output noise
• 0.2 Ω typical output impedance
• Sharp turn-on characteristic, a good Zener diode replacement
• Available in C (0 to 70 °C), I (-40 to 85 °C), and Q (-40 to 125 °C) temperature grades
• TL432 has the same electrical specifications as TL431 with a different pinout for the DBV, DBZ, and PK packages

Applications:

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

Package:

• SOIC-8 (D), 4.90 mm × 3.90 mm
• Other family packages: SOT-23-3 (2.90 × 1.30 mm), SOT-23-5 (2.90 × 1.60 mm), PDIP-8 (9.50 × 6.35 mm), SOP-8 (6.20 × 5.30 mm)

• 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

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

Simplified Schematic

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

NC - No internal connection

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

NC - No internal connection †

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

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

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

See (1)

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.