RT8205L RICHTEK [Richtek Technology Corporation], RT8205L Datasheet - Page 4

• Manufacturer Part Number: RT8205L
• Description: High Efficiency, Main Power Supply Controller for Notebook Computer
• Manufacturer: RICHTEK [Richtek Technology Corporation]

RT8205L/M
Functional Pin Description
www.richtek.com
4
25 (Exposed Pad)
Pin No.
15,
10
12
13
14
16
17
11
1
2
3
4
5
6
7
8
9
ENTRIP1
FB1
REF
TONSEL
FB2
ENTRIP2
VOUT2
VREG3
BOOT2
UGATE2
PHASE2
LGATE2
EN
SKIPSEL
GND
VIN
VREG5
Pin Name
Frequency Selectable Input for VOUT1/VOUT2 respectively.
400kHz/500kHz : Connect to VREG5 or VREG3
300kHz/375kHz : Connect to REF
Operation Mode Selectable Input.
Connect to VREG5 or VREG3 : Ultrasonic Mode
Connect to REF : DEM Mode
Channel 1 Enable and Current Limit Setting Input. Connect a resistor to GND to
set the threshold for channel 1 synchronous R
current limit threshold is 1/10th the voltage seen at ENTRIP1 over a 0.515V to 3V
range. There is an internal 10μA current source from VREG5 to ENTRIP1. Leave
ENTRIP1 floating or drive it above 4.5V to shutdown channel 1.
SMPS1 Feedback Input. Connect FB1 to a resistive voltage divider from VOUT1
to GND to adjust output from 2V to 5.5V.
2V Reference Output. Bypass to GND with a minimum 0.22μF capacitor. REF
can source up to 100μA for external loads. Loading REF degrades FBx and
output accuracy according to the REF load regulation error.
200kHz/250kHz : Connect to GND
SMPS2 Feedback Input. Connect FB2 to a resistive voltage divider from VOUT2
to GND to adjust output from 2V to 5.5V.
Channel 2 Enable and Current Limit Setting Input. Connect a resistor to GND to
set the threshold for channel 2 synchronous R
current limit threshold is 1/10th the voltage seen at ENTRIP2 over a 0.515V to 3V
range. There is an internal 10μA current source from VREG5 to ENTRIP2. Leave
ENTRIP2 floating or drive it above 4.5V to shutdown channel 1.
Bypass Pin for SMPS2. Connect to the SMPS2 output to bypass efficient power
for VREG3 pin. VOUT2 is also for the SMPS2 output soft-discharge.
3.3V Linear Regulator Output.
Boost Flying Capacitor Connection for SMPS2. Connect to an external capacitor
according to the typical application circuits.
Upper Gate Driver Output for SMPS2. UGATE2 swings between PHASE2 and
BOOT2.
Switch Node for SMPS2. PHASE2 is the internal lower supply rail for the
UGATE2 high side gate driver. PHASE2 is also the current sense input for the
SMPS2.
Lower Gate Drive Output for SMPS2. LGATE2 swings between GND and
VREG5.
Master Enable Input. The REF/VREG5/VREG3 are enabled if it is within logic
high level and disabled if it is less than the logic low level.
Connect to GND : PWM Mode
Ground for SMPS Controller. The exposed pad must be soldered to a large PCB
and connected to GND for maximum power dissipation.
Supply Input for 5V/3.3V LDO and Feed Forward On Time Circuitry.
5V Linear Regulator Output. VREG5 is also the supply voltage for the lower gate
driver and analog supply voltage for the device.
Pin Function
DS(ON)
DS(ON)
sense. The GND − PHASE1
sense. The GND − PHASE2
DS8205L/M-05 June 2011
To be continued