TPS60251 Datasheet, PDF (1/28 Pages) Texas Instruments – HIGH EFFICIENCY CHARGE PUMP FOR 7 WLEDs WITH I2C INTERFACE

TPS60251
www.ti.com
SLVS767 – APRIL 2007
HIGH EFFICIENCY CHARGE PUMP FOR 7 WLEDs WITH I²C INTERFACE
FEATURES
• 3.0-V to 6.0-V Input Voltage Range
• ×1 and ×1.5 Charge Pump
• Fully Programmable Current with I²C
– 64 Dimming Steps with 25mA Maximum
(Sub and Main Display Banks)
– 4 Dimming Steps with 80mA Maximum
(DM5 for Auxiliary Application)
• 2% Current Matching for Sub LEDs at Light
Load Condition (Each 100µA)
• 750-kHz Charge Pump Frequency
• Continuous 230-mA Maximum Output Current
• Auto Switching Between ×1 and ×1.5 Mode for
Maximum Efficiency
• Built-in Soft Start and Current Limit
• Hardware Enable/Disable
• Open Lamp Detection
• 24-Pin 4mm x 4mm QFN
APPLICATIONS
• Cellular Phones
• PDA, PMP, GPS (Up To 4 Inch Display)
• Multidisplay Handheld Devices
DESCRIPTION
The TPS60251 is a high efficiency, constant
frequency charge pump DC/DC converter that uses a
dual mode 1× and 1.5× conversion to maximize
efficiency over the input voltage range. It drives up to
five white LEDs for a main display and up to two
white LEDs for a sub display with regulated constant
current for uniform intensity. By utilizing adaptive
1×/1.5× charge pump modes and very low-dropout
current regulators, the TPS60251 achieves high
efficiency over the full 1-cell lithium-battery input
voltage range.
Four enable inputs, ENmain, ENsub1, ENsub2, and
ENaux, available through I²C, are used for simple
on/off controls for the main, sub1, sub2, and DM5
displays, respectively. To lower operating current
when using one sub display LED, the device
provides independent operation in sub display LEDs.
The TPS60251 is available in a 24-pin 4mmx4mm
thin QFN.
Main Display
C4
4.7uF
C2 C3
1uF 1uF
GND IS DM4 DM3 DM 2 DM1
NC
C 1-
C 2+
NC-G
C2-
GND
C 1+
GND
VOUT
NC
VIN
VIO
SDAT ENA DS 1 DS 2 DM5
C1
1uF
SCLK
Auxiliary Port for Key Pad
or Flash Light
I²C Interface
1.8V for I /O
Input
Sub Display
95
90
85
80
75
70
65
60
55 _{4 Main LED - 15 mA, VF = 3.1 V}
50
3 3.5 4 4.5 5 5.5 6
V_I - Input Voltage - V
Figure 1. Typical Application for Sub and Main
Figure 2. Efficiency vs Input Voltage
ORDERING INFORMATION⁽¹⁾
PART NUMBER
TPS60251RTW
PACKAGE
24 Pin 4 mm × 4 mm QFN (RTW)
T_A
–40°C to +85°C
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2007, Texas Instruments Incorporated