AT1397A/B
Preliminary Product Information
6-Channel DC-DC Converter for DSC
VBAT
15V
PVCC4
CH6
OUT6
Voltage-Mode
Step-Up PWM
FB6
COMP6
SS6
IN
/SHDN GND
FB
OUT
+
-
1.24V
AT1202
Figure 6. +15V and –7.5V CCD Bias with Charge-Pump (using AT1202 to regulated the negative output)
Soft-Start Setting (CH1~CH6)
The AT1397A/B all channels feature a soft-start function that limits inrush current and
prevents excessive battery loading at start-up by ramping the output voltage of each
channel up to the regulation voltage. However that CH2 to CH6 start until the CH1
reaches regulation. Consider the input voltage and load current to design the capacitor
connected to the SS pin. It can calculate the CH1~6 soft start time Ts(s)(valid
threshold 0.3~0.8V interval).
∆V
∆t
C ×
= I
Ts(s) = 0.5× C(µF)
Note : It could be disabled soft start function by floating SS pin.
7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
1/10/2006
REV:1.0
18
AIMTRON [ AIMTRON TECHNOLOGY ]
