AT1397A Datasheet, PDF (13/21 Pages) Aimtron Technology – 6-Channel DC-DC Converter for DSC

AT1397A/B
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Application Information
The AT1397A/B includ 6 channels DC/DC to generate a multiple-output digital
camera power-supply system. It include :
z Step-Down DC/DC converter with on-chip synchronous MOSFETs.(CH1, CH2)
z Main synchronous DC/DC controller for Step-Down converter.(CH3)
z Selectable DC/DC controller for boost/flyback/buck/inverting converters.(CH4)
z White LED driver with open LED protection or boost controller.(CH5)
z Boost/flyback controller.(CH6)
Step-Down DC/DC Converter (CH1, CH2)
The step-down DC/DC is optimized for generating DSP voltage (down to 0.8V) at
high efficiency. It runs from the voltage at PVCC1/PVCC2. This pin can be connected
directly to the battery if sufficient headroom exists to avoid dropout.
The CH2 also features an open-drain /SDOK output that goes low when the CH2 is in
regulation. /SDOK may be used to drive an external P-MOSFET that gates 3V power
to the LENs after the DSP_IO voltage is in regulation (Figure 1). The R1,R2 and C1
is for MOSFET soft-start function to avoid the more inrush current .
Step-Down DC/DC Converter (CH3)
The CH3 is step-down voltage mode PWM converter. An external MOSFET and
synchronous rectifier allow conversion efficiencies as high as 93%. Step-down
operation can be direct from Li-Ion cell if the minimum input voltage exceeds the
desired output by approximately 200mV.
7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: [phone] Fax: [phone]
WWW: http://www.aimtron.com.tw
1/10/2006 REV:1.0
Email: [e-mail]
13