CAT4201TD-GT3 ON Semiconductor, CAT4201TD-GT3 Datasheet - Page 10

• Manufacturer Part Number: CAT4201TD-GT3
• Description: IC LED DRIVER HIGH BRIGHT TSOT-5
• Manufacturer: ON Semiconductor
• Type: HBLED Driverr

Specifications of CAT4201TD-GT3

• Topology: PWM, Step-Down (Buck)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Automotive, Backlight
• Type - Secondary: High Brightness LED (HBLED)
• Frequency: 1MHz
• Voltage - Supply: 6.5 V ~ 36 V
• Voltage - Output: 36V
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-5, TSOT-5, TSOP-5
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 350mA
• Internal Switch(s): Yes
• Efficiency: 94%
• Number Of Segments: 1
• Operating Supply Voltage: 6.5 V to 28 V
• Maximum Supply Current: 0.4 mA
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: CAT4201TD-GT3TR

PWM on RSET Pin
another resistor with a FET in series, as shown on Figure 27.
R1 sets the minimum LED current corresponding to 0% duty
cycle. The combined resistor of R1 and Rmax sets the
maximum LED current corresponding to 100% duty cycle.
to provide better accuracy.
PWM
control
VBAT
0 V
12 V
5 V
Another dimming method is to place in parallel to R1
VBAT
A resistor value for R1 of less than 90 kW is recommended
13 V
300
250
200
150
100
Rmax
50
4.7 mF
0
4.7 mF
PWM
control
100
C1
C1
10 kW
R1
Figure 25. LED Current vs. Duty Cycle
OFF ON
Figure 26. Circuit for PWM on CTRL
Figure 27. Circuit for PWM on RSET
R1
1 kW
80
R4
VBAT
RSET
CTRL
CTRL
VBAT
RSET
CAT4201
CAT4201
GND
GND
DUTY CYCLE [%]
60
47 kW
R5
SW
SW
D
D
40
22 mH
22 mH
1 kW
1 kW
R2
10 mF
L
R2
L
10 mF
C2
C2
20
Q1
Q1
http://onsemi.com
NPN
NPN
0
10
Operation from High Supply Voltage Above 14 V
recommended to have a slew rate of 1 ms or more for every
5 V increase in VBAT supply. When using a high supply
voltage of 24 V, a 1 W or 2 W resistor in series with the supply,
as shown on Figure 28, is recommended to limit the slew rate
of the supply voltage. A 4.7 mF minimum ceramic capacitor
is placed between the VBAT pin and ground. The
combination of the series resistor R3 and input capacitor C1
acts as a low pass filter limiting the excessive in−rush
currents and overvoltage transients which would otherwise
occur during “hot−plug” conditions, thereby protecting the
CAT4201 driver.
Operation from High Supply Voltage of 36 V
resistor in series with the supply is recommended, as shown
on Figure 29, to limit the slew rate of the supply voltage.
Parallel Configuration for Driving LEDs Beyond
350 mA
driving LEDs with current in excess of 350 mA. The
CAT4201 driver circuits are connected to the same LED
cathode. Figure 30 shows the application schematic for
driving 1 A into one LED with three CAT4201 connected in
parallel. Each CAT4201 is driving the LED with a current set
by its RSET resistor. The resulting LED current is equal to
the sum of each driver current.
VBAT
VBAT
24 V
36 V
For operation from a supply voltage above 14 V, it is
When powering from a high supply voltage of 36 V, a 2 W
Several CAT4201 devices can be connected in parallel for
1 W
2 W
R3
R3
10 kW
10 kW
4.7 mF
4.7 mF
Figure 28. 24 V Application with 5 LEDs
Figure 29. 36 V Application with 6 LEDs
R1
R1
C1
C1
RSET
CTRL SW
RSET
CTRL SW
VBAT
VBAT
CAT4201
CAT4201
GND
GND
1 kW
1 kW
R1
R2
D1
D1
33 mH
47 mH
4.7 mF
2.2 mF
L
L
C2
C2
300 mA
300 mA