Texas Instruments TPS61181(82/81A)-259 Evaluation Board TPS61181(82/81A)EVM-259 TPS61181EVM-259 TPS61181EVM-259 Benutzerhandbuch
Produktcode
TPS61181EVM-259
60
65
70
75
80
85
90
95
100
0
20
40
60
80
100
120
I
- Output Current - mA
O
Efficiency-%
V
= 19 V
IN
V
= 11 V
IN
V
= 7 V
IN
0
10
20
30
40
50
60
70
80
90
100
0
20
40
60
80
100
120
I
- Output Current - mA
O
Efficiency-%
V
= 19 V,
IN
V
= 11 V,
V
= 7 V
IN
IN
Input/Output Connector Descriptions
2.1.11
JFB1R-JFB6R
These jumpers and the corresponding series resistors are not used in testing the TPS61181 or
TPS61182.
TPS61182.
2.2
Test Setup
Connect a power supply capable of supplying up to 24 V at 1.5 A is required between the VBAT pin and
GND (J1 and J2). Connect a second logic signal or power supply capable of providing 1.2 V - 7 V to the
high-impedance EN pin (J3) referenced to the same ground on J2. For normal operation, JP13 should be
shorted with a jumper or ammeter and multiple WLEDs connected to one or more of the IFBx lines. J8
provides a convenient connection to WLEDEVM-260 (SLVU238) via a 14-pin ribbon, which contains six
strings of 12 WLEDs each. Alternatively, external WLEDs can be connected to J2 or between jumpers
JFB1S - JFB6S. If fewer than six WLEDs are needed, simply leave the unused IFBx line unconnected or
short it to ground. By shorting jumpers JFB1S - JFB6S, the user can test the IC's protection against short
circuits.
GND (J1 and J2). Connect a second logic signal or power supply capable of providing 1.2 V - 7 V to the
high-impedance EN pin (J3) referenced to the same ground on J2. For normal operation, JP13 should be
shorted with a jumper or ammeter and multiple WLEDs connected to one or more of the IFBx lines. J8
provides a convenient connection to WLEDEVM-260 (SLVU238) via a 14-pin ribbon, which contains six
strings of 12 WLEDs each. Alternatively, external WLEDs can be connected to J2 or between jumpers
JFB1S - JFB6S. If fewer than six WLEDs are needed, simply leave the unused IFBx line unconnected or
short it to ground. By shorting jumpers JFB1S - JFB6S, the user can test the IC's protection against short
circuits.
The TPS6118x family implements WLED dimming by replicating the PWM signal applied to DCTRL pin to
the IFBx internal current regulators. A function generator capable of providing 1.2-V to 6-V maximum
amplitude PWM signal between 100 Hz to 1 kHz is required to implement dimming, avoid screen
flickering, and maintain dimming linearity.
the IFBx internal current regulators. A function generator capable of providing 1.2-V to 6-V maximum
amplitude PWM signal between 100 Hz to 1 kHz is required to implement dimming, avoid screen
flickering, and maintain dimming linearity.
2.3
Test Results
Below are the test results at T
A
= 25
°
C using this EVM:
Figure 1. Efficiency vs Total WLED Output Current
Figure 2. Dimming Linearity
4
TPS61181EVM-259 / TPS61182EVM-259
SLVU223B
–
February 2008
–
Revised May 2011
Copyright
©
2008
–
2011, Texas Instruments Incorporated