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STR-A6251 Datasheet – Flyback Switching Regulator

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Part Number: STR-A6251

Function: PWM-topology off-line secondary-feedback switching regulator IC

Package: DIP 8 Pin Type

Manufacturer: Allegro MicroSystems, Sanken

Images:

STR-A6251 datasheet

 

Description

The STR-A6251 and STR-A6252 are 50 kHz PWM topology (with ±5% frequency jittering for minimum EMI) regulators specifically designed to satisfy the requirements for increased integration and reliability in flyback converters. They incorporate a primary control and drive circuit with avalanche-rated power MOSFETs.

The STR-A6252 features higher allowable switching current and lower on-resistance.
The STRA6251 is also available for 67 kHz operation. Covering the power range from below 21 watts or 24 watts for a 230 VAC input, or to 15 or 20 watts for a universal (85 to 264 VAC) input, these devices can be used in a wide range of applications, from DVD players and VCR player/recorders to ac adapters for cellular phones and digital cameras. An auto-burst standby function reduces power consumption at light load, while multiple protections, including the avalanche-energy guaranteed MOSFET, provide high reliability of system design.

Pinouts

STR-A6251 pinout

 

 

Features

1. Start-up circuit

Thanks to the proprietary 900V BCD process, the built-in startup circuit connected to the internal MOSFET drain reduces both the discrete component count and the power consumption.

2. PWM operational frequency jittering

The frequency jittering function suppresses EMI noise and consequently reduces the EMI noise filter cost The center frequency of PWM operation is set to 50 KHz, and the frequency jittering provides variation of Δf= 5KHz (typ), which is adjustable by the external capacitor.

3. Over Load Protection (OLP) with a built-in timer (Auto restart)

Built-in delay timer circuit to trip the overload protection requires no external OLP capacitor, which allows cost reduction and space-saving.

Preview

STR-A6251 pinout datasheet

 

Applications

1.Standby power supply

2.Battery charger

3.Small power S.M.P.S

STR-A6251 Datasheet PDF

STR-A6251 pdf

TMP122 Datasheet – Digital Temperature Sensor ( PDF )

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Part Number: TMP122

Function: 1.5°C Accurate Programmable Digital Temperature Sensor

Package: SOT23-6 and SO-8 Type

Manufacturer: Burr-Brown (Texas Instruments)

Image

TMP122 datasheet pdf

Description

TMP122 is a digital temperature sensor with an SPI-compatible interface, designed for accurate and low-power thermal monitoring across a wide temperature range. It integrates sensing, A/D conversion, and digital communication into a compact device, making it suitable for embedded systems, industrial control, and portable electronics.

Requiring only a pull-up resistor for complete function, the TMP122 and TMP124 temperature sensors are capable of measuring temperatures within 2°C of accuracy over a temperature range of –40°C to +125°C, with operation up to 150°C.

Programmable resolution, programmable set points and shutdown function provide versatility for any application. Low supply current and a supply range from 2.7V to 5.5V make the TMP122 and TMP124 excellent candidates for low power applications. The TMP122 and TMP124 are ideal for extended thermal measurement in a variety of communication, computer, consumer, environmental, industrial, and instrumentation applications.

Features

  • SPI-compatible digital interface
  • Programmable resolution: 9-bit to 12-bit + sign
  • High accuracy:
    • ±1.5°C (–25°C to +85°C max)
    • ±2.0°C (–40°C to +125°C max)
  • Low quiescent current: ~50 µA
  • Wide supply voltage: 2.7V to 5.5V
  • Supports operation up to 150°C
  • Programmable high/low temperature setpoints
  • Shutdown mode for power saving
  • Compact packages: SOT23-6, SO-8

Pinout

TMP122 datasheet

Functional Description

  • Measures temperature using an internal sensor and converts it into digital data via integrated ADC
  • Communicates temperature data through SPI interface (clock, data, chip select)
  • Resolution is configurable, allowing trade-off between precision and conversion time
  • Includes programmable threshold registers for thermal alert or control systems

Interface Notes

  • SPI-compatible (typically 3-wire or 4-wire configuration)
  • Requires only a pull-up resistor for proper operation
  • Easy integration with MCU, DSP, or FPGA systems

Design Notes

  • Place sensor close to heat source for accurate measurement
  • Avoid PCB thermal gradients and self-heating effects
  • Use proper grounding and decoupling to minimize noise on SPI lines
  • Configure resolution based on required response time vs accuracy
  • Utilize shutdown mode in battery-powered applications

How to Choose This Sensor

  • Choose when SPI interface is preferred over I²C
  • Suitable for moderate accuracy (±1.5~2°C) applications
  • Ideal for low-power and space-constrained designs
  • Consider TMP124 for similar functionality with package variation

Typical Applications

  • Notebook and desktop thermal management
  • Industrial temperature monitoring
  • Power supply thermal protection
  • Environmental sensing systems
  • Instrumentation and measurement equipment

Alternative / Equivalent Products

  • TMP124 (similar with different packaging)
  • LM75 (I²C interface alternative)
  • TMP102 (ultra-low power I²C sensor)
  • ADT7310 (higher accuracy SPI temperature sensor)

Other data sheets are available within the file:

TMP122AIDBVR, TMP122AIDBVRG4, TMP122AIDBVT, TMP122AIDBVTG4

TMP122 Datasheet PDF Download


TMP122 pdf