Bench Test Setup Conditons
5.1
Headers Description
Header
Function
LOC
Placement
Comment
Number
For immediate start-up fit jumper to V3V
JP11
BUCK1 enable (EN1)
SW
For sequencing do not fit jumper
Fit according to test requirement
To disable converter fit jumper to GND
For immediate start-up fit jumper to V3V
JP20
BUCK2 enable (EN2)
SW
For sequencing do not fit jumper
Fit according to test requirement
To disable converter fit jumper to GND
For immediate start-up fit jumper to V3V
JP3
BUCK3 enable (EN3)
SW
For sequencing do not fit jumper
Fit according to test requirement
To disable converter fit jumper to GND
Do not leave this header open.
For forced PWM operation fit jumper to V3V
Use a jumper to set either
JP25
Forced PWM (F_PWM)
S
For automatic PFM/PWM operation fit
forced PWM mode or automatic
jumper to GND
PFM/PWM mode
USB1 enable
For automatic start-up fit jumper to V3V
JP34
SW
Fit according to test requirement
(USB1EN)
To disable SWITCH fit jumper to GND
JP35
USB1_nFAULT
E
USB1 fault indicator pulled to 3V3
Fit according to test requirement
JP26
INT
S
Interruption fault indicator pulled to 3V3
Fit according to test requirement
JP27
PGOOD
S
PGOOD indicated pulled to 3V3
Fit according to test requirement
5.2
Test Points and Placement
Buck converter outputs are white and have a label for easy location. Close to any of these test points
there are black ground test points to allow for DVM measurement or to use a metal exposed scope probe
to reduce common mode noise measurements. All test points are described in the following table:
Test Point
Name
Signal
COLOR
Comment
TP1
GND
GND
White
TP2
GND
GND
White
TP3
GND
GND
White
TP4
Vin
Vin
Black
TP5
GND
GND
White
TP6
GND
GND
White
TP7
GND
GND
White
TP14
Vout1
Output voltage Buck1
Not fitted
Injection Point gain-phase measurement
Normally not
TP14a
Not fitted
buck1
used
TP17
Vout1
Output voltage Buck2
Not fitted
Injection Point gain-phase measurement
Normally not
TP17a
Not fitted
buck2
used
TP37
Vout1
Output voltage Buck3
Not fitted
Injection Point gain-phase measurement
Normally not
TP37a
Not fitted
buck3
used
TP32
USB1_Vin
USB1 switch input
Black
TP33
USB1_Vo
USB1 switch output
Black
7
SLVU568
–
September 2011
TPS65257 High Current, Synchronous Step Down Three Buck Switcher
Evaluation Module with 1USB Switch and Push Button Controller
Copyright
©
2011, Texas Instruments Incorporated
