CAT3661HV3-GT2 ON Semiconductor, CAT3661HV3-GT2 Datasheet - Page 9

• Manufacturer Part Number: CAT3661HV3-GT2
• Description: IC INTERFACE
• Manufacturer: ON Semiconductor
• Series: QUAD-Mode®r
• Type: Backlight, White LEDr

Specifications of CAT3661HV3-GT2

• Constant Current: *
• Constant Voltage: *
• Topology: *
• Number Of Outputs: *
• Internal Driver: *
• Type - Primary: *
• Type - Secondary: *
• Frequency: *
• Voltage - Supply: *
• Voltage - Output: *
• Mounting Type: Surface Mount
• Package / Case: 16-WFDFN, Exposed Pad
• Operating Temperature: *
• Current - Output / Channel: *
• Internal Switch(s): Yes
• Efficiency: 92%
• Led Driver Application: Backlighting
• No. Of Outputs: 1
• Output Current: 5mA
• Output Voltage: 7V
• Input Voltage: 2V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Driver Case Style: TQFN
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: CAT3661HV3-GT2OSTR

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 the LED current, the
device remains in 1x operating mode.
the LED regulated current 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).
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 the LED current 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
At power−up, the CAT3661 starts operating in 1x mode
If the input voltage is insufficient or falls to a level where
This sequence repeats in the 1.33x and 1.5x mode until the
If the device detects a sufficient input voltage is present to
Figure 24. CAT3661 Functional Block Diagram
http://onsemi.com
9
mode is called the 1x mode transition hysteresis (V
is about 300 mV.
LED Current Setting
the current in the LED channel with a gain of 300. The LED
current can be adjusted from 0.1 mA to 5 mA. Connecting
a resistor between RSET and GND allows a reference
current to flow due to the voltage on the RSET pin being
regulated to 0.6 V. The internal gain of the current mirror is
300. It is possible to calculate the current in the LED channel
by the following equation:
Adjustable Battery Indicator
indicator that is active when the device is enabled. If the
voltage on the internal resistor divider trip point node is less
than V
remains low for 500 ms after the EN pin is driven high. The
CAT3661 will still function normally below this voltage
The current flowing out of the RSET pin to ground mirrors
The CAT3661 contains an adjustable low battery
ADJ
(0.6 V), the nFLTB output is driven low and
I
LED
+
0.6 V
R
SET
300
HYS
) and