Si9139 Datasheet, PDF (12/17 Pages) Vishay Siliconix – Multi-Output, Individual On/Off Control Power-Supply Controller

Si9139
Vishay Siliconix
New Product
TIMING DIAGRAMS
ON_A or ON_B
V_IN
V_L
V_REF
OSC EN
(Sysmon EN)
OSC
0.8 V
f_max (SS)
DH
t_BBM
4 ms
The converter is enabled
V_IN is applied
LDO is activated after V_IN is
applied
REF circuit is activated after V_L
becomes available
After V_REF goes above 0.8 V,
the converter is turned on
Oscillator is activated
Slow soft-start gradually increases
the maximum inductor current
High-side gate drive duty ratio
gradually increases to maximum
D_L
Low-side gate drive
FIGURE 2. Converter is Enabled Before V_IN is Applied, A or B controllers
ON_A or ON_B
V_IN
V_L
V_REF
OSC EN
(Sysmon EN)
OSC
f_max (SS)
DH
0.8 V
4 ms
The converter is enabled
V_IN is applied
LDO is activated after V_IN is
applied
REF circuit is activated after V_L
becomes available
After V_REF goes above 0.8 V,
the converter is turned on
Oscillator is activated
Slow soft-start gradually increases
the maximum inductor current
DL
www.vishay.com
12
FIGURE 3. Converter is Enabled After V_IN is Applied, A or B Controllers
Document Number: 71841
S-22317—Rev. A, 16-Dec-02