LV5604TA Datasheet, PDF (10/12 Pages) Sanyo Semicon Device – Bi-CMOS LSI Eight-Channel Switching Regulator Controller

Continued from preceding page.
Pin No. Pin Name
Description
46
VCC
Signal system power supply
2
VBIAS1
Power system power supply
47
VBIAS2
(Output stage)
24
GND_S
Signal system GND
58 GND_P1 (VS1) Output stage GND
54 GND_P2 (VS2) (Output stage GND)
50
(NC)
Use prohibited
63
(NC)
(Not connected pins)
LV5604TA
Equivalent Circuit
VCC
VBIAS*
GND_S
GND_P*(VS*)
(NC)
Notes
(1) Channel 8 step-up/step-down selection function
The channel 8 step-up or step-down converter selection is made by the SEL_8CH pin connection.
Step-up/step-down is selected by SEL_CH8, but this selection cannot be switched during use, and is fixed to either
step-up or step-down in the design stage. In addition, unlike other channels, channel 8 is not connected internally to a
pull-up/pull-down resistor, so an external resistor must be connected instead.
(Mode selection using SEL_CH8)
Selected mode
SEL_CH8 connection
Step-down (DOWN converter)
VBIAS2
Step-up (UP converter)
GND_P2 (VS2)
OUT8 resistor connection
Connect to VBIAS2 via a resistor (between the PchTr gate and VBIAS2)
Connect to GND_P2 (VS2) via a resistor
(between the NchTr gate and GND_P2 (VS2))
(2) Soft start time setting method
The soft start time is set with the capacitor connected between CSOFT* and GND_S.
This IC has an independent soft start function for each channel, so a capacitor must be connected for each channel to
set the soft start (time).
(Description of soft start operation)
(Outline of soft start pin)
CSOFT* [V]
VB ( = 0.515 [V] (TYP))
CSOFT* voltage
VREG
(Internal constant voltage)
T [s]
Soft start time (Tsoft [s])
CSOFT pin
charging starts
The output voltage reaches the
set voltage
(Output voltage constant)
200kΩ
VB (0.515 [V])
CSOFT*
GND_S
(3) Setting the oscillation frequency
The internal oscillation frequency is set by the resistor connected to the RT pin and the capacitor connected to the CT
pin. The waveform generated on CT is a triangular wave with the charging/discharging waveform determined by RT
and CT.
fOSC
=
CT
1
×
RT
[Hz]
The actual internal oscillation frequency deviates from the calculated value due to overshoot, undershoot and other
factors, so the frequency should be confirmed in an actual set.
No.A2027-10/12