CAT3644HV3-T2 ON Semiconductor, CAT3644HV3-T2 Datasheet - Page 10

• Manufacturer Part Number: CAT3644HV3-T2
• Description: IC LED DRVR WHITE BCKLGT 16-TQFN
• Manufacturer: ON Semiconductor
• Series: QUAD-Mode®r
• Type: Backlight, White LEDr

Specifications of CAT3644HV3-T2

• Topology: Switched Capacitor (Charge Pump)
• Number Of Outputs: 4
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: White LED
• Frequency: 800kHz ~ 1.6MHz
• Voltage - Supply: 2.5 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 16-TFQFN Exposed Pad
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 25mA
• Internal Switch(s): Yes
• Efficiency: 92%
• Number Of Segments: 4
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Lead Free Status / Rohs Status: Details
• Other names: CAT3644HV3-T2CT

Block Diagram
Basic Operation
where the output will be approximately equal to the input
supply voltage (less any internal voltage losses). If the
output voltage is sufficient to regulate all LED currents, the
device remains in 1x operating mode.
the regulated currents cannot be maintained, the device
automatically switches into 1.33x mode (after a fixed delay
time of about 400 ms). In 1.33x mode, the output voltage is
approximately equal to 1.33 times the input supply voltage
(less any internal voltage losses).
At power−up, the CAT3644 starts operating in 1x mode
If the input voltage is insufficient or falls to a level where
V
EN/DIM
IN
100 kΩ
Registers
Interface
Serial
Figure 25. CAT3644 Functional Block Diagram
4/3x, 3/2x, 2x Charge Pump
C
Setting DAC
Reference
1−
1, 1.3 MHz
Oscillator
Voltage
Current
1x mode (LDO)
C
1+
RSET
http://onsemi.com
C
2−
Mode Control
10
C
2+
driver enters the 2x mode. In 1.5x mode, the output voltage
is approximately equal to 1.5 times the input supply voltage.
While in 2x mode, the output is approximately equal to 2
times the input supply voltage.
drive all LED currents in 1x mode, it will change
automatically back to 1x mode. This only applies for
changing back to the 1x mode. The difference between the
input voltage when exiting 1x mode and returning to 1x
mode is called the 1x mode transition hysteresis (V
is about 500 mV.
This sequence repeats in the 1.33x and 1.5x mode until the
If the device detects a sufficient input voltage is present to
GND
Current Regulators
V
LED Channel
LED1
LED2
LED3
LED4
OUT
HYS
) and