HT7463A Datasheet, PDF (1/16 Pages) Holtek Semiconductor Inc – 52V/600mA, 1.25MHz/550kHz Asynchronous Step Down Converter

HT7463A/HT7463B
52V/600mA, 1.25MHz/550kHz
Asynchronous Step Down Converter
Features
• Wide Input Voltage Range 4.5V to 52V
• 52V / 0.9Ω Internal Power MOSFET
• 600mA Peak Output Current
• Up to 90% Efficiency
• 1.25MHz (HT7463A) and 550kHz (HT7463B)
Fixed Operating Frequency
• Ultra Low Shutdown Current < 1µA
• Output Short Circuit Protection
• Thermal Shutdown Protection
• Package Type: SOT23-6
Applications
• Power Meters
• Distribution Power Systems
• Battery Chargers
• Pre-Regulator for Linear Regulators
General Description
The HT7463A/B is a current mode buck converter.
With a wide input range from 4.5V to 52V,
the HT7463A/B is suitable for a wide range of
applications such as power conditioning from
unregulated sources. Having a low internal switch
typical RDSON value of 0.9Ω, the device has a good
operating typical efficiency value of 85% and the
added advantage of reduced junction temperature.
The operating frequency is fixed at 1250/550kHz for
the HT7463A/HT7463B respectively. The HT7463A
allows the use of small external components while
still being able to have low output voltage ripple.
A soft-start function can be implemented using the
enable pin and by connecting an external RC circuit
allowing the user to tailor the soft-start time to a
specific application.
Application Circuit
CB
0.1µF
L1
22µH/47µH *³
HT7463A/B
1 _CB
SW ⁶
2 _GND
3 _FB
VIN ⁵
EN ⁴
D1
On/Off
Control
C3
0.1µF
C4
22µF *²
C1
0.1µF
VIN
C2
100µF
VOUT=12V *¹
R2
6kΩ / ±1%
R1
84kΩ / ±1%
Note: *1. C4=330μF is recommended to achieve 1‰ output ripple requirement
*2. Set R1=84kΩ and R2=16kΩ for V_OUT=5V application
*3. It’s recommended that L1=22μH for HT7463A and L1=47μH for HT7463B
Rev. 1.11
1
August 12, 2016