TLV431x Low-Voltage Adjustable Precision Shunt Regulator
1 Features
• Low-Voltage Operation, VREF = 1.24 V
• Adjustable Output Voltage, VO = VREF to 6 V
• Reference Voltage Tolerances at 25°C
– 0.5% for TLV431B
– 1% for TLV431A
– 1.5% for TLV431
• Typical Temperature Drift
– 4 mV (0°C to 70°C)
– 6 mV (–40°C to 85°C)
– 11 mV (–40°C to 125°C)
• Low Operational Cathode Current, 80 µA Typical
• 0.25-Ω Typical Output Impedance
• Ultra-Small SC-70 Package Offers 40% Smaller Footprint Than
SOT-23-3
• See TLVH431 and TLVH432 for:
– Wider VKA (1.24 V to 18 V) and IK (80 mA)
– Additional SOT-89 Package
– Multiple Pinouts for SOT-23-3 and SOT-89 Packages
• On Products Compliant to MIL-PRF-38535, All Parameters Are Tested
Unless Otherwise Noted. On All Other Products, Production
Processing Does Not Necessarily Include Testing of All Parameters.
2 Applications
• Adjustable Voltage and Current Referencing
• Secondary Side Regulation in Flyback SMPSs
• Zener Replacement
• Voltage Monitoring
• Comparator With Integrated Reference
3 Description
The TLV431 device is a low-voltage 3-terminal adjustable voltage
reference with specified thermal stability over applicable
industrial and commercial temperature ranges. Output voltage can be
set to any value between VREF (1.24 V) and 6 V with two external
resistors (see the Parameter Measurement Information section).
These devices operate from a lower voltage (1.24 V) than the widely
used TL431 and TL1431 shunt-regulator references.
When used with an optocoupler, the TLV431 device is an ideal
voltage reference in isolated feedback circuits for 3-V to 3.3-V
switching-mode power supplies. These devices have a typical output
impedance of 0.25 Ω. Active output circuitry provides a very sharp
turnon characteristic, making them excellent replacements for
low-voltage Zener diodes in many applications, including on-board
regulation and adjustable power supplies.
Device Information(1)
| PART NUMBER | PACKAGE (PIN) | BODY SIZE (NOM) |
TLV431x | SOT-23 (3) | 2.90 mm × 1.30 mm |
| SOT-23 (5) | 2.90 mm × 1.60 mm |
| SC70 (6) | 2.00 mm × 1.25 mm |
| TO-92 (3) | 4.30 mm × 4.30 mm |
| SOIC (8) | 4.90 mm × 3.90 mm |
For all available packages, see the orderable addendum at the end
of the data sheet.
4.Specifications
4.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
| MIN MAX | UNIT |
| VKA Cathode voltage(2) | 7 | V |
| IK Continuous cathode current | –20 20 | mA |
| Iref Reference current | –0.05 3 | mA |
| Operating virtual junction temperature | 150 | °C |
| Tstg Storage temperature | –65 150 | °C |
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other
conditions beyond those indicated under Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for
extended periods may affect device reliability.
(2) Voltage values are with respect to the anode terminal, unless
otherwise noted.
4.2 ESD Ratings
| PARAMETER | DEFINITION | VALUE | UNIT |
| V(ESD) Electrostatic discharge | Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) | ±2000 |
V |
| Charged device model (CDM), per JEDEC specification JESD22-C101,
all pins(2) | ±1000 |
(1) JEDEC document JEP155 states that 500-V HBM allows safe
manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe
manufacturing with a standard ESD control process.
4.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
| MIN MAX | UNIT |
| VKA Cathode voltage | VREF 6 | V |
| IK Cathode current | 0.1 15 | mA |
TA Operating free-air temperature | TLV431_C | 0 70 |
°C |
| TLV431_I | –40 85 |
| TLV431_Q | –40 125 |
4.4 Thermal Information
THERMAL METRIC(1) | TLV431x |
UNIT |
| DCK | D | PK | DBV | DBZ | LP |
| 6 PINS | 8 PINS | 3 PINS | 5 PINS | 3 PINS | 3 PINS |
| RθJA Junction-to-ambient thermal resistance | 87 | 97 | 52 | 206 | 206 | 140 | °C/W |
| RθJC(top) Junction-to-case (top) thermal resistance | 259 | 39 | 9 | 131 | 76 | 55 | °C/W |
(1) For more information about traditional and new thermal metrics,
see the Semiconductor and
IC Package Thermal Metrics application report (SPRA953).
4.1 Electrical Characteristics for TLV431
at 25°C free-air temperature (unless otherwise noted)
PARAMETER |
T |
EST CONDITIONS | TLV431 |
UNIT |
| MIN | TYP | MAX |
VREF |
Reference voltage |
VKA = VREF, IK = 10 mA | TA = 25°C | 1.222 | 1.24 | 1.258 |
V |
TA = full range(1) (see Figure 22) | TLV431C | 1.21 | | 1.27 |
| TLV431I | 1.202 | | 1.278 |
| TLV431Q | 1.194 | | 1.286 |
VREF(dev) |
VREF deviation over full temperature range(2) |
VKA = VREF, IK = 10 mA(1) (see Figure 22) | TLV431C | | 4 | 12 |
mV |
| TLV431I | | 6 | 20 |
| TLV431Q | | 11 | 31 |
OVREF 
OVKA | Ratio of VREF change in cathode voltage change | VKA = VREF to 6 V, IK = 10 mA (see Figure 23) | |
–1.5 |
–2.7 |
mV/V |
Iref |
Reference terminal current | IK = 10 mA, R1 = 10 kΩ, R2 = open (see Figure 23) | |
0.15 |
0.5 |
µA |
Iref(dev) |
Iref deviation over full temperature range(2) | IK = 10 mA, R1 = 10 kΩ, R2 = open(1) (see Figure 23) | TLV431C | | 0.05 | 0.3 |
µA |
| TLV431I | | 0.1 | 0.4 |
| TLV431Q | | 0.15 | 0.5 |
| IK(min) | Minimum cathode current for regulation | VKA = VREF (see Figure 22) | TLV431C/I | | 55 | 80 |
µA |
| TLV431Q | | 55 | 100 |
| IK(off) | Off-state cathode current | VREF = 0, VKA = 6 V (see Figure 24) | 0.001 0.1 | µA |
| |zKA| | Dynamic impedance(3) | VKA = VREF, f ≤ 1 kHz, IK = 0.1 mA to 15 mA (see Figure 22) | | 0.25 | 0.4 | Ω |
(1) Full temperature ranges are –40°C to 125°C for TLV431Q, –40°C
to 85°C for TLV431I, and 0°C to 70°C for TLV431C.
