AS3722 Datasheet, PDF (20/198 Pages) –

AS3722 − Detailed Descriptions- Power Management Functions
Detailed Descriptions-
Power Management Functions
DCDC Step-Down Converter
Description
The step-down converter is a high efficiency fixed frequency
current mode regulator. By using low resistance internal PMOS
and NMOS switches efficiency up to 95% can be achieved. The
fast switching frequency allows using small inductors, without
increasing the current ripple. The unique feedback and
regulation circuit guarantees optimum load and line regulation
over the whole output voltage range, up to an output current
of 1.5A (SD4, SD5), 2A (SD3) and 5A for SD2, with an output
capacitor of only 8-27μF. The implemented current limitation
protects the DCDC and the coil during overload condition.
Figure 9:
Step Down DC/DC Converter Block Diagram
sdx_low_noise
clk
Overvoltage
Ref +8%
Comp
skip
250/400/600mA
Imin
1.2/1.8/2.9A
Ilimit
IsenseP
VSUP_SDx
LX_SDx
sdX_lv
Ref -5%
PWM
Comp
Slope
Compensation
Zero Comp
IsenseN
skip
Ref=0.6V
softstart
VSS_SDx
FB_SDx
DCDC Step Down Converter Block Diagram: Shows the internal structure of the DCDC bucks.
Page 20
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ams Datasheet
[v1-01] 2015-Sep-07