TPS60255 Datasheet, PDF (1/25 Pages) Texas Instruments – HIGH EFFICIENCY CHARGE PUMP FOR 7 WLEDs DRIVER WITH 1 WIRE INTERFACE

TPS60255
www.ti.com
SLVS825 – MARCH 2008
HIGH EFFICIENCY CHARGE PUMP FOR 7 WLEDs DRIVER WITH 1 WIRE INTERFACE
FEATURES
1
•2 2.7 V to 6.0 V Input Voltage Range
• 1× and 1.5× Charge Pump
• Auto Switching Between 1× and 1.5× Modes
• 750 kHz Charge Pump Frequency
• Seven Individually-regulated WLED
Current Sinks
• Single- Wire Interface for Dimming and
ON/OFF Control
• 25 mA max LED Current for Six Current Sinks
• One 80 mA Current Sink
• Open WLED Detection
• Built-in Soft Start and Current Limit
• 16-pin, 3 mm × 3 mm QFN Package
APPLICATIONS
• Cellular Phones
• Portable Navigation Displays
• Multi-display Handheld Devices
DESCRIPTION
The TPS60255 is a high-efficiency, constant
frequency charge pump DC/DC converter that uses
1× and 1.5× conversion to maximize efficiency for the
input voltage range. By using adaptive 1×/1.5×
charge-pump modes and very low dropout current
regulators, the TPS60255 achieves high efficiency for
the entire one-cell lithium battery range. The
protection features include soft start, over-current
limit, thermal shut down, and over-voltage detection.
The device automatically detects and removes
unused current sinks from the control loop.
This device drives six 25 mA current sinks and one
80 mA current sink. These current regulators are
programmed by three independent brightness
registers and five ON/OFF bits using a single-wire
interface (EasyScale™). This offers flexible
applications for a variety of lighting control in portable
devices.
AUX
GND GC GA4 GA3
C1-
GA2
Back Light
for
LCD Display
C2+
C2 C3
1 mF 1 mF
C2-
GA1
GB2
C1+
VOUT
VIN ENA
GB1
IF
C4
C1
2.2 mF 4.7 mF
Enable/
Disable
Interface Using
EasyScale
Figure 1. Typical Application
100
V_IN = Sweep Down
90
4 LEDs: GA1, GA2, GA3, and GA4
* LED: NSSW100CT (NICHIA)
80
70
60
ILED = 15.3 mA
50 _{ILED = 25.2 mA}
40
2.9
3.4
ILED = 2.1 mA
3.9
4.4
V_IN − Input Voltage − V
Figure 2. Characteristic Curve
a
4.9
G001
ORDERING INFORMATION⁽¹⁾
PART
NUMBER
TPS60255RTE
PACKAGE
MARKING
BUP
PACKAGE
16-Pin 3 mm × 3 mm QFN (RTE)
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.
1
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.
EasyScale is a trademark of Texas Instruments.
2
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 © 2008, Texas Instruments Incorporated