CAT3644HV3-GT2 ON Semiconductor, CAT3644HV3-GT2 Datasheet - Page 11

• Manufacturer Part Number: CAT3644HV3-GT2
• Description: IC LED DVR 4CH QUAD MODE 16TQFN
• Manufacturer: ON Semiconductor
• Series: QUAD-Mode®r
• Type: Backlight, White LEDr

Specifications of CAT3644HV3-GT2

• Topology: Linear (LDO), 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
• Voltage - Output: 7V
• 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 Digits: 4
• Low Level Output Current: 25 mA
• High Level Output Current: 100 mA
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Supply Current: 30 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

LED Current Selection
(100% brightness) by the external resistor R
enables and disables the device. The other function is LED
current dimming with six different levels by pulsing the
* The gain is changed on the rising edges of the EN/DIM input.
Table 7. LED CURRENT DIMMING LEVELS
At power−up, the initial LED current is set to full scale
The EN/DIM pin has two primary functions. One function
EN/DIM # of Pulses *
LED
Current
EN/DIM
EN = High
2
3
4
5
6
1
x
nd
st
rd
th
th
th
th
LED current + 132
Shutdown
T
SETUP
T
LED
100%
Figure 26. EN/DIM Digital Dimming Timing Diagram
0.6 V
R
SET
SET
Device cycling through gain selection
as follows:
50%
T
http://onsemi.com
LO
T
HI
25%
R
SET
4.125
16.5
8.25
132
132
66
33
11
Gain
12.5% 6.25%
input signal, as shown on Figure 26. On each consecutive
pulse rising edge, the LED current is divided by half to 50%,
then 25%, 12.5%, 6.25% and 3.125% dimming levels.
Pulses faster than the minimum T
filtered by the device. Pulses longer than the maximum T
may shutdown the device.
EN/DIM is held low for 1.5 ms or more.
The LED driver enters a “zero current” shutdown mode if
3.12%
100%
T
PWRDWN
4.125 x 0.6 V / R
GAIN x 0.6 V / R
LO
16.5 x 0.6 V / R
8.25 x 0.6 V / R
132 x 0.6 V / R
132 x 0.6 V / R
66 x 0.6 V / R
33 x 0.6 V / R
LED Current
may be ignored and
Shutdown
SET
SET
SET
SET
SET
SET
SET
SET
LO