MAX1574ETB+T Maxim Integrated Products, MAX1574ETB+T Datasheet - Page 5

• Manufacturer Part Number: MAX1574ETB+T
• Description: IC LED DRVR WHITE BCKLGT 10-TDFN
• Manufacturer: Maxim Integrated Products
• Type: Backlight, White LEDr

Specifications of MAX1574ETB+T

• Constant Current: Yes
• Topology: Linear (LDO), Switched Capacitor (Charge Pump)
• Number Of Outputs: 3
• Internal Driver: Yes
• Type - Primary: Backlight, Flash/Torch
• Type - Secondary: White LED
• Frequency: 1MHz
• Voltage - Supply: 2.7 V ~ 5.5 V
• Voltage - Output: 5V
• Mounting Type: Surface Mount
• Package / Case: 10-TDFN Exposed Pad
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 60mA
• Internal Switch(s): Yes
• Efficiency: 83%
• Number Of Segments: 3
• Low Level Output Current: 60 mA
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Supply Current: 2 mA
• Maximum Power Dissipation: 1454 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

(Circuit of Figure 2, V
PIN
10
—
1
2
3
4
5
6
7
8
9
NAME
LED3
LED2
LED1
GND
OUT
SET
CN
EN
CP
EP
IN
_______________________________________________________________________________________
IN
V
= 3.6V, EN = IN, driving three white LEDs, T
I
180mA, 1x/2x, White LED Charge Pump
V
OUT
OUT
EN
Supply Voltage Input. Connect a 0.47µF to 1µF ceramic capacitor from IN to GND. The input voltage
range is 2.7V to 5.5V. IN is high impedance during shutdown.
Enable and Dimming Control. Pulsing EN low dims the LEDs in multiple steps. Drive low for longer than
2ms (typ) to shut down the IC. From shutdown, drive EN high (50µs min) to set I
current (see the SETfunction). Pulse EN low for 0.5µs to 500µs to dim the LEDs (Figure 1).
Transfer-Capacitor Positive Connection. Connect a 0.22µF capacitor from CP to CN.
Transfer-Capacitor Negative Connection. Connect a 0.22µF capacitor from CP to CN.
Current-Set Input. Connect a resistor (R
I
LED_ Cathode Connection. Current flowing into LED_ is based on SET description above. In 2x mode,
the charge pump regulates the lowest LED_ voltage to 0.18V. Connect LED_ to IN for unpopulated LEDs.
LED_ is high impedance during shutdown.
Ground. Connect GND to system ground and as close as possible to the input-bypass capacitor ground.
Output. Connect a 0.47µF to 1µF ceramic capacitor from OUT to GND, and connect OUT to the anodes
of all the LEDs. OUT is pulled to ground through an internal 5k resistor in shutdown.
Exposed Paddle. Connect the exposed paddle directly to GND underneath the IC.
LED(MAX)
DIMMING RESPONSE
= 393
10ms/div
0.6V / R
Typical Operating Characteristics (continued)
MAX1574 toc10
SET
. SET is internally biased to 0.6V. SET is high impedance during shutdown.
2V/div
50mA/div
2V/div
A
SET
= +25°C, unless otherwise noted.)
) from SET to GND to set the maximum LED current.
FUNCTION
in 3mm x 3mm TDFN
V
I
OUT
OUT
V
IN
LINE TRANSIENT 3.8V TO 3.3V TO 3.8V
100µs/div
Pin Description
MAX1574 toc11
LED
to the maximum
1V/div
1V/div
60mA,
20mA/div
5