RT8206A RICHTEK [Richtek Technology Corporation], RT8206A Datasheet - Page 6

• Manufacturer Part Number: RT8206A
• Description: High-Efficiency, Main Power Supply Controllers for Notebook Computers
• Manufacturer: RICHTEK [Richtek Technology Corporation]

RT8206A/B
BOOT1
Boost Flying Capacitor Connection for SMPS1. Connect
to an external capacitor according to the typical application
circuits.
LGATE1
SMPS1 Synchronous-Rectifier Gate-drive Output. LGATE1
swings between PGND and PVCC.
PVCC
PVCC is the supply voltage for the low-side MOSFET
driver LGATEx. Connect a 5V power source to the PVCC
pin (bypass with 1uF MLCC capacitor to PGND if
necessary). There is an internal 10Ω connecting from
PVCC to VCC. Make sure that both VCC and PVCC are
bypassed with 1uF MLCC capacitors.
SECFB
The SECFB is used to monitor the optional external 14V
charge pump. Connect a resistive voltage-divider from the
14V charge pump output to GND to detect the output. If
SECFB drops below the threshold voltage, LGATE1 will
be turned on for 300ns. This will refresh the external charge
pump driven by LGATE1 without over-discharging the
output voltage.
NC (Pin 20) (RT8206B)
No Internal Connection.
GND
Analog Ground for both SMPS and LDO. The exposed
pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
PGND
Power Ground for SMPS controller. Connect PGND
externally to the underside of the exposed pad.
LGATE2
SMPS2 Synchronous-Rectifier Gate-drive Output. LGATE2
swings between PGND and PVCC.
BOOT2
Boost Flying Capacitor Connection for SMPS2. Connect
this pin to an external capacitor according to the typical
application circuits.
www.richtek.com
6
[Pin 21,
(Pin 19)
(Pin 22)
(Pin 20) (RT8206A)
(Pin 17)
(Pin 24)
(Pin 18)
(Pin 23)
Exposed Pad (33)]
PHASE2
Inductor Connection for SMPS2. PHASE2 is the internal
lower supply rail for the UGATE2 high-side gate driver.
PHASE2 is the current-sense input for the SMPS2.
UGATE2
High-Side MOSFET Floating Gate-Driver Output for
SMPS2. UGATE2 swings between PHASE2 and BOOT2.
EN2
SMPS2 Enable Input. The SMPS2 will be enabled if EN2
is greater than the logic high level and be disabled if EN2
is less than the logic low level. If EN2 is connected to
REF, the SMPS2 starts after the SMPS1 reaches
regulation (delay start). Drive EN2 below 0.8V to clear
fault level and reset the fault latches.
PGOOD2
SMPS2 Power-Good Open-Drain Output. PGOOD2 is low
when the SMPS2 output voltage is more than 7.5% below
the normal regulation point or during soft-start. PGOOD2
is high impedance when the output is in regulation and
the soft-start circuit has terminated. PGOOD2 is low in
shutdown.
SKIP
SMPS Operation Mode Control.
SKIP = GND : DEM operation
SKIP = REF : Ultrasonic Mode operation
SKIP = VCC : PWM operation.
VOUT2
SMPS2 Output Voltage-Sense Input. Connect this pin to
the SMPS2 output. VOUT2 is an input to the constant
on-time-PWM one-shot circuit. It also serves as the
SMPS2 feedback input in fixed-voltage mode.
ILIM2
SMPS2 Current-Limit Adjustment. The GND − PHASE2
current-limit threshold is 1/10th the voltage seen at ILIM2
over a 0.5V to 2V range. There is an internal 5uA current
source from VCC to ILIM2. The logic current limit threshold
is default to 100mV value if ILIM2 is higher than (VCC −
1V).
(Pin 27)
(Pin 29)
(Pin 31)
(Pin 30)
(Pin 26)
(Pin 25)
(Pin 28)
DS8206A/B-04 March 2011