CURRENT MODE PWM POWER SWITCH
DESCRIPTION
The UTC US3706 combines a dedicated current mode PWM
controller with a high voltage power MOSFET. Low VDD startup
current make the power reliable on startup design and a large
value resistor could be used in the startup circuit to minimize the
standby power. At no load condition, the IC operates in
power-saving mode for lower standby power, decreasing frequency
for Higher conversion efficiency at light load condition.
The UTC US3706 offers complete protection coverage with
automatic self-recovery feature including Cycle-by-Cycle current
limiting (OCP), over load protection (OLP), over temperature
protection (OTP), over voltage protection and VDD under
voltage lockout (UVLO).
The internal slope compensation improves system stability at
high PWM duty cycle output. Leading-edge blanking on current
sense input removes the signal glitch, which offering minimal
external component count in the design. Excellent EMI
performance is achieved with UTC proprietary frequency hopping
technique (ZL201020615247.1) together with soft driver control.
Audio noise is eliminated due to switch frequency more than 20kHz
during operation.
The US3706 has such applications as: battery charger, power
adaptor, set-top box power supplies, ink jet printers, open-frame SMPS
FEATURES
* UTC proprietary frequency hopping technology for Improved EMI performance.
* Power-saving mode for high light-load and standby efficiency
* Soft Start
* Dynamic peak current limiting for constant output power
* Built-in synchronized slope compensation
* OLP,OVPand OTP for higher security
* Fixed switch frequency 65kHz
* Low start-up current
* Cycle-by-cycle Current Limiting
* Under voltage lockout (UVLO)
* Leading edge blanking on source input
* Few external components required |
