ZHCSQN2 December 2023 TPS1200-Q1
ADVANCE INFORMATION
- 1
- 1 特性
- 2 应用
- 3 说明
- 4 Pin Configuration and Functions
- 5 Specifications
- 6 Parameter Measurement Information
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3
Feature Description
- 7.3.1 Charge Pump and Gate Driver Output (VS, PU, PD, BST, SRC)
- 7.3.2 Capacitive Load Driving Using FET Gate (PU, PD) Slew Rate Control
- 7.3.3 Short-Circuit Protection
- 7.3.4 Overvoltage (OV) and Undervoltage Protection (UVLO)
- 7.3.5 Reverse Polarity Protection
- 7.3.6 Short-Circuit Protection Diagnosis (SCP_TEST)
- 7.3.7 TPS12000-Q1 as a Simple Gate Driver
- 7.4 Device Functional Modes
- 8 Application and Implementation
- 9 Device and Documentation Support
- 10Revision History
- 11Mechanical, Packaging, and Orderable Information
7.3.3 Short-Circuit Protection
The TPS12000-Q1 feature adjustable short circuit protection. The threshold and response time can be adjusted using RISCP resistor and CTMR capacitor respectively. The device senses the voltage across CS+ and CS– pins.
These pins can be connected across an external high and low side current sense resistor (RSNS) as or across the FET drain and source terminals for FET RDSON sensing shown in Figure 7-5, Figure 7-6, Figure 7-7 and Figure 7-8 respectively.
Figure 7-5 TPS12000-Q1 Application
Circuit With External Sense Resistor RSNS Based High Side Current
Sensing
Figure 7-6 TPS12000-Q1 Application
Circuit With MOSFET RDSON Based Current Sensing
Figure 7-7 TPS12000-Q1 Application
Circuit With External Sense Resistor RSNS Based Low Side Current Sensing on
Battery Side
Figure 7-8 TPS12000-Q1 Application
Circuit With External Sense Resistor RSNS on Based Low Side Current Sensing
on Load SideSet the short-circuit detection threshold using an external RISCP resistor across ISCP and GND pins. Use Equation 5 to calculate the required RISCP value:
Refer to Equation 9 in Section 8.1.1 section for update in equation in final revision of IC.
Where,
RSNS is the high or low side current sense resistor value or the FET RDSON value.
ISC is the desired short circuit current level.
The short circuit protection response is fastest with no CTMR cap connected across TMR and GND pins.
With device powered ON and EN/UVLO, INP pulled high, During Q1 turn ON, first VGS of external FET is sensed by monitoring the voltage across PD to SRC. Once PD to SRC voltage raises above V(G_GOOD) (7.5 V typical) threshold which ensures that the external FET is enhanced, then the SCP comparator output is monitored. If the sensed voltage across CS+ and CS– exceeds the short-circuit set point (VSCP), PD pulls low to SRC and FLT asserts low. Subsequent events can be set either to be auto-retry or latch off as described in following sections.
VGS of external FET (Q1) is only monitored when CS_SEL is pulled low. VGS of external FET (Q1) is not monitored for low side current sensing as shown Figure 7-7 and Figure 7-8.