Pic16F887

®

TL431
PROGRAMMABLE VOLTAGE REFERENCE

. . . .

ADJUSTABLE OUTPUT VOLTAGE : 2.5 to 36V SINK CURRENT CAPABILITY : 1 to 100mA TYPICAL OUTPUT IMPEDANCE : 0.22Ω 1% AND 2% VOLTAGE PRECISION
Z TO92 (Plastic Package)

N DIP8 (Plastic Package)

DESCRIPTION The TL431 is a programmable shunt voltage reference with guaranteed temperature stability over the entire temperature range ofoperation. The output voltage may be set to any value between Vref (approximately 2.5V) and 36V with two external resistors. The TL431 operates with a wide current range from 1 to 100mA with a typical dynamic impedance of 0.22Ω. PIN CONNECTIONS
TO92 (Top view)
8

D SO8 (Batwing Plastic Micropackage)

ORDER CODES
Part number Temperature Range TL431C/AC TL431I/AI 0oC, +70oC -40oC, +105oC Package Z • •N • • D • •

DIP8 (Top view)
7 6 5 8

SO8 (Top view)
7 6 5

Cathode Anode Refere nce
1 2 3

1 2 3 4 5 6 7 8
1 2 3 4

- Cathode - N.C. - N.C. - N.C. - N.C. - Anode - N.C. - Reference
1 2 3 4

1 2 3 4 5 6 7 8

- Cathode - Anode - Anode - N.C. - N.C. - Anode - Anode - Reference

November 1998

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TL431

ABSOLUTE MAXIMUM RATINGS
Symbol VKA IK Iref Toper Tstg ParameterCathode to Anode Voltage Continuous Cathode Current Range Reference Input Current Range Operating Free-air Temperature Range TL431C/AC TL431I/AI Storage Temperature Range Value 37 -100 to +150 -0.05 to +10 0 to +70 -40 to +105 -65 to +150 Unit V mA mA
o

C C

o

OPERATING CONDITIONS
Symbol VKA IK Cathode Current Parameter Cathode to Anode Voltage Value Vref to 36 1 to 100 Unit V mAELECTRICAL CHARACTERISTICS Tamb = 25oC (unless otherwise specified)
Symbol Vref ∆Vref ∆Vref ∆VKA Iref Parameter TL431C Min. Typ. Max. Min. 2.47 2.453 TL431AC Typ. 2.495 Max. 2.52 2.537 mV 3 17 3 15 mV/V -1.4 -1 -2.7 -2 -1.4 -1 -2.7 -2 µA 1.8 4 5.2 1.8 4 5.2 µA 0.4 1.2 0.4 1.2 mA 0.5 2.6 0.22 1 1000 0.5 0.5 2.6 0.22 0.6 1000 0.5 nA Ω Unit V

Reference Input Voltage - (figure 1) o Tamb = 25 C 2.442.495 2.55 VKA = Vref, IK = 10mA Tmin. ≤ Tamb ≤ Tmax. 2.423 2.567 Reference Input Voltage Deviation Over Temperature Range - (figure 1, note1) VKA = Vref, IK = 10mA, T min. ≤ Tamb ≤ T max. Ratio of Change in Reference Input Voltage to Change in Cathode to Anode Voltage - (figure 2) ∆VKA = 10V to Vref IK = 10mA ∆VKA = 36V to 10V Reference Input Current - (figure 2) IK = 10mA, R 1 = 10kΩ, R 2 = ∞ Tamb= 25oC Tmin. ≤ Tamb ≤ Tmax. Reference Input Current Deviation Over Temperature Range - (figure 2) IK = 10mA, R 1 = 10kΩ, R 2 = ∞ Tmin. ≤ Tamb ≤ Tmax. Minimum Cathode Current for Regulation - (figure 1) VKA = Vref Off-State Cathode Current - (figure 3) Dynamic Impedance - (figure 1, note 2) VKA = Vref, ∆IK = 1 to 100mA, f ≤ 1kHz

∆Iref

Imin Ioff |ZKA|
Notes : 1.

∆Vref is defined as thedifference between the maximum and minimum values obtained over the full temperature range. ∆Vref = Vref max. - Vref min V ref ma x.
V re fmin. T1 T2 Tempe ra tur e

2.

The dynamic Impedance is defined as |ZKA| =

∆VKA ∆IK

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TL431
ELECTRICAL CHARACTERISTICS Tamb = 25oC (unless otherwise specified)
Symbol Vref ∆Vref ∆Vref ∆VKA Iref Parameter Reference Input Voltage - (figure 1) oTamb = 25 C VKA = Vref, IK = 10mA Tmin. ≤ Tamb ≤ Tmax. Reference Input Voltage Deviation Over Temperature Range - (figure 1, note1) VKA = Vref, IK = 10mA, T min. ≤ Tamb ≤ T max. Ratio of Change in Reference Input Voltage to Change in Cathode to Anode Voltage - (figure 2) ∆VKA = 10V to Vref IK = 10mA ∆VKA = 36V to 10V Reference Input Current - (figure 2) IK = 10mA, R 1 = 10kΩ, R 2 = ∞ Tamb = 25oCTmin. ≤ Tamb ≤ Tmax. Reference Input Current Deviation Over Temperature Range - (figure 2) IK = 10mA, R 1 = 10kΩ, R 2 = ∞ Tmin. ≤ Tamb ≤ Tmax. Minimum Cathode Current for Regulation - (figure 1) VKA = Vref Off-State Cathode Current - (figure 3) Dynamic Impedance - (figure 1, note 2) VKA = Vref, ∆IK = 1 to 100mA, f ≤ 1kHz TL431I Min. 2.44 2.41 Typ. 2.495 Max. 2.55 2.58 Min. 2.47 2.44 TL431AI Typ....