SNVU822 May   2022

 

  1.   Trademarks
  2. 1Introduction
  3. 2Warnings and Cautions
  4. 3Description
    1. 3.1 Typical Applications
    2. 3.2 Features
    3. 3.3 Connector and Test Point Description
    4. 3.4 Electrical Performance Specifications
  5. 4Test Setup
    1. 4.1 Input Supplies and LED Load Connections
    2. 4.2 Analog Duty Cycle Control Using APWM
    3. 4.3 Analog Dimming Using IADJ
    4. 4.4 PWM Dimming Using nExt_PWM Test Points
    5. 4.5 Switching Frequency Set Point Using RON
  6. 5Performance Data and Typical Characteristic Curves
    1. 5.1 Efficiency
    2. 5.2 Analog Dimming
    3. 5.3 PWM Dimming
    4. 5.4 PWM Dimming Waveforms
  7. 6Schematic
  8. 7TPS92643EVM-204 PCB Layout
  9. 8Bill of Materials

3.3 Connector and Test Point Description

This section describes the connectors and test points on the EVM and how to properly connect, setup, and use the TPS92643EVM-204.

Figure 3-1 TPS92643EVM-204 Top View – EVM Functions and Features
Figure 3-2 TPS92643EVM-204 Bottom View – EVM Functions and Features
This section describes the connectors, names, and descriptions.
Figure 3-3 TPS92643EVM-204 Connector Numbers and Locations
Table 3-1 Connectors
Connector Description
J1

J1 allows for a creating a harness that connector to VOUT+ (pin 1) and GND (pin 2).
J2 J2 allows for a creating a harness that connector to VIN (pin 1) and GND (pin 2).

This section describes the test points, names, and descriptions.

Figure 3-4 TPS92643EVM-204 Test point Numbers and Locations
Table 3-2 Test Points
Test Point Description
GND (TP3, TP4, TP7, TP11) Larger metal turrets and test points allow for multiple connection to grounds across the board.
VIN (TP5) The VIN test point allows for voltage and current measurement of the power applied to the VIN pin of the
TPS92643-Q1.

VCC (TP6)

 The VCC test point is connected to TPS92643's internal 5-V linear supply output.
VOUT+ (TP1) The VOUT+ test point allows for connection of the LED loads to the output. Large turrets allow for multiple connections.

SW (TP2)

The SW test point allows for observing the switch node for the output during operation with an oscilloscope.

nExt_PWM (TP10)

nExt_PWM test point allows for the indirect connection of the UDIM pin through the use of a N-FET (Q1) on the UDIM pin of the TPS92643-Q1 for PWM dimming of the output. UDIM (TP13) is inverted from the nExt_PWM signal. Read the External PWM Dimming and Input Undervoltage Lockout (UVLO) section in the TPS92643-Q1 Automotive 3-A Synchronous Buck LED Driver data sheet for additional information.

APWM (TP9)

 This test point is the test point used to perform analog duty cycle control of the 1.6-kHz PWM output. The APWM pin is by default pulled to 5 V, which means it is at 100% duty cycle. The duty cycle starts from 1 V and 0% duty cycle and goes to 2.5 V which is 100% duty cycle. For example, 1.75 V is 50% duty cycle of the 1.6-kHz PWM signal.
nFLT (TP12) The nFLT test point can be used to monitor if a fault has occurrence on the TPS92643-Q1 output. When a fault occurs, nFLT voltage level goes low. Read the Faults and Diagnostics section of the TPS92643-Q1 Automotive 3-A Synchronous Buck LED Driver data sheet to determine which faults trigger the nFLT indication.

IADJ (TP8)

 The TPS92643-Q1's LED current are controlled by applying a voltage to the IADJ test point. 133 mV to 2.45 V for VIADJ gives 190 mA to 3000 mA of output current.

UDIM (TP13)

UDIM is the undervoltage lockout and PWM input. Connecting VIN through a resistor divider to implement input undervoltage protection. Diode, N-FET, or NPN couple signal to enable dimming.