CAT3637HV3-GT2 ON Semiconductor, CAT3637HV3-GT2 Datasheet - Page 12

• Manufacturer Part Number: CAT3637HV3-GT2
• Description: IC LED DRVR WHITE BCKLGT 16-TQFN
• Manufacturer: ON Semiconductor
• Series: QUAD-Mode®r
• Type: Backlight, White LEDr

Specifications of CAT3637HV3-GT2

• Topology: Switched Capacitor (Charge Pump)
• Number Of Outputs: 6
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: White LED
• Frequency: 600kHz ~ 1.4MHz
• 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: 30mA
• Internal Switch(s): Yes
• Efficiency: 92%
• Number Of Segments: 6
• 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: CAT3637HV3-GT2TR

Unused LED Channels
disabled by connecting the LED pin directly to VOUT, as
shown on Figure 26. If LED pin voltage is within 1 V of
Protection Mode
automatically limits at about 5.5 V. This is to prevent the
output pin from exceeding its absolute maximum rating.
enter a thermal protection shutdown mode. When the device
temperature drops by about 20°C the device will resume
normal operation.
LED Selection
5.0 V may be used with the CAT3637. Selecting LEDs with
lower V
by keeping the driver in 1x mode longer as the battery
voltage decreases.
over one with V
for lower supply voltage of 0.2 V. This helps improve the
efficiency and extends battery life.
External Components
for decoupling input, output, and for the charge pump. Both
capacitors type X5R and X7R are recommended for the
LED driver application. In all charge pump modes, the input
current ripple is kept very low by design and an input bypass
capacitor of 1 mF is sufficient.
not introduce switching noise back onto the supply.
For applications with 5 LEDs or less, unused LEDs can be
If an LED is disconnected, the output voltage VOUT
If the die temperature exceeds +150°C the driver will
LEDs with forward voltages (V
For example, if a white LED with a V
The driver requires two external 1 mF ceramic capacitors
In 1x mode, the device operates in linear mode and does
F
is recommended in order to improve the efficiency
F
of 3.5 V, the CAT3637 will stay in 1x mode
2.5 V
5.5 V
to
Programming
V
1−Wire
IN
1 mF
C
IN
F
) ranging from 1.3 V to
F
VIN
EN/SET
C1−
of 3.3 V is selected
CAT3637
C1+
1 mF
Figure 26. Five LED Application
GND
C2−
VOUT
http://onsemi.com
LED1
LED2
LED3
LED4
LED5
LED6
C2+
1 mF
12
VOUT, then the channel is switched off and a 200 mA test
current is placed in the channel to sense when the channel
moves below VOUT – 1 V.
Recommended Layout
high frequency. It is recommended to minimize trace length
to all four capacitors. A ground plane should cover the area
under the driver IC as well as the bypass capacitors. Short
connection to ground on capacitors C
implemented with the use of multiple via. A copper area
matching the TQFN exposed pad (TAB) must be connected
to the ground plane underneath. The use of multiple via
improves the package heat dissipation.
In charge pump mode, the driver switches internally at a
Figure 27. Recommended Layout
V
OUT
C
1 mF
OUT
IN
and C
OUT
can be