Texas Instruments TPS1HC100, Руководство пользователя

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5 Current Limit and Current Sense Configuration
The current limit resistor connected to the ILIM pin configures the current limit of the TPS1HC100-Q1 device.
Based off the limit of this resistor the allowed current that passes through the high side switch can be controlled.
The TPS1HC100EVM provides three different ways of configuring the effective value of the resistance on the
ILIM pin:
• With a physical potentiometer labeled "Current Limit"
• Using a soldered down resistor
R6
• Via I2C using an onboard digital potentiometer U2 (TPL0102-100)
See the Table 4-2 section for details on how to configure each one of these jumpers.
For the digital potentiometer option, the user has the ability to control the current limit via the TPL0102-100
digital potentiometer with I2C. The SDA and SCL lines of the digital potentiometer are connected to the
standardized
J1-9 and J1-10 pins of the BoosterPack header. Both pins are pulled up with pull-up resistors
connected to the LaunchPad's 3.3-V power rail. For more details on how to program the TPL0102-100 device,
refer to the
TPL0102-100 data sheet .
In the TPS1HC100EVM, both channels of the digital potentiometer are connected in series with each other,
allowing for a greater resolution of configurable current limit value. The slave address of the TPL0102-100 is
configured to be
0x56 . To configure the current limit, a simple 3-byte I2C write transaction must be performed
to set the configured resistance value. The first byte should be 0x00 (corresponding to the resistance value
register) and the next two bytes should be the corresponding resistance codes from the table in Appendix
- TPL0102-100 Resistance Codes . These two values will add up in series to make up the total resistance
connected to the ILIM pin of the TPS1HC100B-Q1. Once the STOP condition is written via the I2C line, the
configured resistance value takes effect on the TPL0102-100.
For the current sense resistance connected to the SNS pin, the "SNS Pot Enable" jumper will control the
source. If this jumper is populated, the "SNS" potentiometer is used to increase and decrease the resistance
connected to the SNS pin. If this jumper is not populated, the solder down pad
R13 should be used to provide
the necessary resistance value. The output of the TPS1HC100B-Q1's SNS pin is an analog current that is a
representation of the load current going through the switch. The purpose of the sense resistor is to convert
this current into a voltage so that an ADC can convert it into a value for a microcontroller to use. For the
TPS1HC100EVM, the voltage across the sense resistor can either be read externally via the SNS test point or
from the BoosterPack's standardized analog
J1-6 pin.
Current Limit and Current Sense Configuration www.ti.com
6 TPS1HC100 Evaluation Module SLVUC30 – JULY 2021
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