RT8450BGCP Richtek USA Inc, RT8450BGCP Datasheet - Page 3

• Manufacturer Part Number: RT8450BGCP
• Description: IC LED DRIVER PWM 16TSSOP
• Manufacturer: Richtek USA Inc

Specifications of RT8450BGCP

• Internal Driver: Yes
• Type - Primary: Backlight
• Mounting Type: Surface Mount
• Topology: PWM, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Frequency: 400kHz ~ 600kHz
• Voltage - Supply: 4.5 V ~ 40 V
• Package / Case: 16-TSSOP (0.173", 4.40mm Width) Exposed pad
• Operating Temperature: -40°C ~ 85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Other names: 1028-1003-2

Functional Pin Description
DS8450/B-02 November 2009
(Exposed Pad)
TSSOP-16
1
2
3
4
5
6
7
Pin No.
WDFN-12L 3x3
PWM
Dimming control
4.5V to 40V
PWM
Dimming control
4.5V to 40V
2
3
4
5
6
7
1
10k
R1
10k
Figure 5. PWM to Analog Dimming Buck-Boost Configuration
C2
3nF
R1
V
C2
3nF
V
5V
IN
5V
IN
Figure 4. PWM to Analog Dimming Boost Configuration
Pin Name
10nF
C3
C3
10nF
ACTL
DCTL
OVP
ISN
ISP
VC
EN
C1
0.5µF
C4
0.5µF
C1
C4
Current Sense Amplifier Positive Input.
Current Sense Amplifier Negative Input. Voltage threshold between
ISP and ISN is 190mV.
PWM Boost Converter Loop Compensation Node.
Analog Dimming Control. Effective programming range is between
0.3V and 1.2V.
By Adding a 0.1μF Filtering Capacitor on ACTL Pin, the PWM
dimming signal on DCTL pin will be averaged and converted into
analog dimming signal on ACTL pin. V
duty cycle .
Chip Enable (Active High), when low chip is in shutdown mode.
Over voltage protection. PWM boost converter turns off when V
goes higher than 1.2V.
VC
SS
ACTL
VCCx
EN
DCTL
VCCx
EN
DCTL
VC
SS
ACTL
RT8450/B
RT8450/B
20uH
L
GND
OVP
GND
OVP
ISN
SW
ISP
ISN
SW
ISP
190mV
20uH
R2
R4
L
Pin Function
190mV
R3
R2
R4
R3
C5
V
C5
1µF
OUT
ACTL
V
V
= 1.2V x PWM dimming
OUT
OUT
RT8450/B
To be continued
www.richtek.com
OVP
3