MAX1848ETA-T Maxim Integrated Products, MAX1848ETA-T Datasheet - Page 5

• Manufacturer Part Number: MAX1848ETA-T
• Description: LED Drivers High-Efficiency Unif orm-Brightness White
• Manufacturer: Maxim Integrated Products

Specifications of MAX1848ETA-T

• Number Of Segments: 3
• Operating Supply Voltage: 2.6 V to 5.5 V
• Maximum Power Dissipation: 1951 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TDFN EP
• Minimum Operating Temperature: - 40 C

(See Typical Application Circuit, V+ = 3V, I
T
A
= +25°C, unless otherwise noted.)
PIN
1
2
3
4
5
6
7
8
V
V
CTRL
I
OUT
LED
_______________________________________________________________________________________
V
NAME
COMP
PGND
CTRL
GND
OUT
CTRL
CS
LX
V+
White LED Step-Up Converter in SOT23
TRANSIENT RESPONSE
20ms/div
Compensation Pin for Error Amplifier. Connect capacitor from COMP to GND. Startup time is set
by the capacitance connected to this pin (0.833ms for each 0.01µF). V
discharges to GND when in shutdown.
Brightness/Shutdown Dual Mode Control Input. LED brightness and IC shutdown are controlled
by the voltage on CTRL. Voltages between 250mV and 5.5V or (V+ + 2V), whichever is less,
adjust the brightness from dim to bright, respectively. To put the IC into shutdown, drive below
100mV or connect to GND.
Overvoltage Sense. When V
off and V
Connect a 1µF capacitor from OUT to GND.
Inductor Connection. Drain of the internal high-voltage N-channel MOSFET.
Power Ground. Source of the internal high-voltage N-channel MOSFET.
Ground
Current-Sense Feedback Input. Connect a resistor from this pin to GND to set the LED bias
current. This pin regulates to 7.5% of V
Supply Voltage Input. The IC is powered from this pin. Input range is 2.6V to 5.5V. Bypass with a
ceramic capacitor to GND.
C
COMP
= 1μF
LED
COMP
MAX1848 toc10
= 15mA, L = 33µH, C
Typical Operating Characteristics (continued)
decays to GND. When V
2.0V
1.0V
6.7V
6.3V
30mA
15mA
OUT
V
is greater than 13.25V, the internal N-channel MOSFET is turned
OUT_RIPPLE
V
OUT
IN_RIPPLE
V
LX
CTRL
= 1µF, C
I
L
OUT
FUNCTION
.
drops below 12.25V, the IC will re-enter soft-start.
SWITCHING WAVEFORMS
COMP
= 0.15µF, R
200ns/div
SENSE
MAX1848 toc11
COMP
Pin Description
= 5Ω, CTRL = 1V, 2 LEDs,
61mA
17mA
10mV/div
10mV/div
6.5V
0
passively
5