1.224V open collector shunt voltage reference
Document overview
- Manufacturer or author: STMICROELECTRONICS
- PDF pages: 8
Technical content
1.224V Open Collector Shunt Voltage Reference ■ Internal 1.224V ±0.5% precision ■ Low output saturation voltage 75 mV max between SINK and GND ■ Low current consumption: 250 µA ■ Industrial temperature range: -40 to +85°C ■ 100ppm/°C temperature coefficient
Description
The TS4431 is a four-terminal device dedicated to low voltage Switch Mode Power Supplies (SMPS). It integrates a 1.224V voltage reference, an amplifier, and an open collector output transistor in a single package. The TS4431’s operating mode is similar to the well-known standard voltage reference, the TL431. It maintains the desired feedback voltage at the REF pin in a closed loop configuration by sinking a current proportional to the error voltage at the REF pin. TS4431 features an open collector transistor with an ultra-low saturation voltage, allowing it to be used in series with the optocoupler in an SMPS architecture to regulate low voltage SMPS.
Applications
■ Low voltage switch mode power supplies ■ Isolated DC/DC converter ■ Computers ■ Low voltage discrete regulator Order Codes SOT23-5L (Plastic Micropackage) Pin connections (top view) Vc c Gnd Nc Re f Sink Part Number Accuracy Temperature Range Package Packing Marking TS4431AILT 0.5% -40, +85°C SOT23-5 Tape & Reel L288 TS4431ILT 1% L275
1 Absolute Maximum Ratings
Table 1. Key parameters and their absolute maximum ratings
- P D has been calculated with TAMB = 25°C, TJunction=150°C and
Table 2. Operating conditions
2 Typical Application Schematic
Figure 1. SMPS power supply: secondary side
3 Electrical Characteristics
Table 3. Electrical characteristics for T amb = 25°C, VCC = 1.8V, ISINK = 2mA unless
4 Package Mechanical Data
In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a Lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: DIM. mm. mils A 0.90 1.45 35.4 57.1 A1 0.00 0.15 0.0 5.9 A2 0.90 1.30 35.4 51.2 b 0.35 0.50 13.7 19.7 C 0.09 0.20 3.5 7.8 D 2.80 3.00 110.2 118.1 E 2.60 3.00 102.3 118.1 E1 1.50 1.75 59.0 68.8 e. 9 5 3 7 . 4 e1 1.9 74.8 L 0.35 0.55 13.7 21.6 SOT23-5L MECHANICAL DATA
5 Revision History
March 2005 1 First release corresponding to Preliminary Data version of datasheet. Nov. 2005 2 First release of fully mature product data sheet. Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this p ublication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicr oelectronics. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners © 2005 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Ital y - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America