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Connector and Test Point Descriptions
7
SLVUBB1–November 2017
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How to Use the TPS65680 Evaluation Module
ADVANCE INFORMATION
4.2 Input Connectors
4.2.1 J4 – LN_CLK - Input and GND Connector
This header is the connection for the LN_CLK input square wave signal. Connect a frequency generator or
microcontroller output between pins 1 and 2 (LN_CLK) and pins 3 and 4 (GND) to supply the device with
the input signal for the internal PLL. The square wave needs to have a frequency from 40 kHz to 500 kHz
and a duty cycle of 40% to 60%.
4.2.2 J5 – LS_START - Input and GND Connector
This header is the connection for the LS_START input signal. Connect a frequency generator or
microcontroller output between pins 1 and 2 (LS_START) and pins 3 and 4 (GND) to supply the device
with the input signal starting the programmed output pattern from the programmed start address. The
LS_START pulse needs to have a pulse width of 15 µs to 500 µs.
4.2.3 J6, J52, and S2 – LS_CNTRL - Input and GND Connectors
The header J6 is the connection for the LS_CNTRL input signal. For programming the TPS65680 this
signal needs to be low, if this signal is set high, the IC is in active mode and the device can be controlled
via the LN_CLK and LS_START signals.
This signal can be driven from an external source, via header J52 or from the GUI.
• GUI: Set switch S2 to SW side
• J52: Set switch S2 to J52 side and use the jumper on J52 to drive the signal high (connect middle pin
to pin 1 (VIN)) or low (connect middle pin to pin 3 (GND))
• External source: Remove the jumper from header J52 and set switch S2 to J52.
4.3 Level-Shifter Output Connectors
4.3.1 J36, J38, J12, J14, J16, J18, J20, J22, J24, J6, J28, J30, J32, J34, J40, J46, J42, and J44 – GSP1,
GSP2, GCK1 to GCK12, GCP, VSS, GGP1 and GGP2 - Output and GND Connectors
These headers are the connection of the 18 level-shifter outputs. Connect a scope probe between pins 1
and 2 (GND) and pins 3 and 4 (output) to measure this specific level shifter output.
4.3.2 J35, J37, J11, J13, J15, J17, J19, J21, J23, J25, J29, J31, J33, J39, J45, J41, and J43 –
Connectors to add load to the level shifter outputs
These headers can be used to add capacitive or RC load to the respective one of the 18 level shifter
outputs. Connect a jumper between pins 1 and 2 (C) to add a capacitive load to the respective level shifter
output or connect a jumper between pins 2 and 3 (RC) to add an RC load to the respective level shifter
output.
4.3.3 J54, J55, J56, J57, J59, J60, J61, J62, J63, J64, and J65 – Connectors to add identical loads to 2
level shifter outputs to measure charge sharing
These headers can be used to add identical RC loads to the respective 2 of the 12 level shifter clock
outputs that are used during charge sharing. Connect a jumper on one of the headers J54 to J59 to add a
load to one of the channels GCK1 to GCK6 and another jumper on one of the headers J60 to J65 to add
an RC load to one of the channels GCK7 to GCK12. If the 2 resistors R26 and R27 and the 2 capacitors
C49 and C50 have the identical values, the output voltages of the channels that are sharing their charge
should meet at the voltage V(VGL) + ((V(VGH) - V(VGL))/2)
NOTE: Be aware that capacitors with the identical theoretical value do not match in reality. For
identical capacitance values you need to measure the capacitors and select two that have
identical values before applying them to the EVM.
