STEVAL-ISA055V2: 3.3V @ 700mA, 5V in

Summary

This demonstration board is based on the ST1S12 family of synchronous step-down DC-DC converters optimized for powering low-voltage digital cores in HDD (hard disk drive) applications and is generally used to replace high-current linear solutions when power dissipation may cause high heating of the application environment.

It provides up to 0.7 A over an input voltage range of 2.5 V to 5.5 V. A high switching frequency of 1.7 MHz allows the use of tiny surface-mount components. For the adjustable version, a resistor divider to set the output voltage value, an inductor, and two capacitors are required. Only an inductor and 2 capacitors are needed for the 1.2 V and 1.8 V fixed version. A low output ripple is guaranteed by the current mode PWM topology and by the use of low ESR surface-mount ceramic capacitors.

The ST1S12 device is thermal protected and current limited to prevent damage due to accidental short-circuit.

Specifications

Manufacturer	STMicroelectronics
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Single Output
Eval Board Part Number	497-8220-ND
Eval Board Supplier	STMicroelectronics
Eval Board	Normally In Stock
Topology	Step Down
Outputs and Type	1 Non-Isolated
Output Voltage: Factory Set	3.3 V
Current Out	700 mA
Voltage In	2.5 ~ 5.5 V
Efficiency @ Conditions	>90%, 5V in, 3.3V @ 50 ~ 700 mA >90%, 5V in, 2.5V @ 100 ~ 500 mA >80%, 5V in, 1.2V @ 60 ~ 600 mA Out
Voltage Out Range	0.6 ~ Vin
Features	Current Limit (Adj. or Fixed) Over Current Protection Shutdown, Enable, Standby Soft Start Thermal Protection Under Voltage Protection, Brown-Out
Switching Frequency	1.7 MHz
Standby Current [Typical]
Quiescent Current [Typical]	500 mA
Component Count + Extras	6 + 2
Internal Switch	Yes
Design Author	STMicroelectronics
Application / Target Market	Computers Point of Load (PoL)
Main I.C. Base Part	ST1S12_ADJ
Standby Current [Maximum]	1 µA
Quiescent Current [Maximum]	600 mA
Date Created By Author
Date Added To Library	2011-03