BQ25792EVM, BQ25798EVM and BQ25798BKUPEVM (BMS034) Evaluation Module
BQ25792EVM, BQ25798BKUPEVM and BQ25798EVM (BMS034) Evaluation Module
This user's guide describes the characteristics, operation, and functionality of the BQ25792 and BQ25798 Evaluation Module (EVM). It will also describe the equipment, test setup, and software required to operate the EVM. A complete schematic diagram, printed-circuit board (PCB) layouts, and bill of materials (BOM) are also included in this document.
Throughout this user's guide, the abbreviations and terms EVM, BQ2579XEVM, BMS034, and evaluation module are synonymous with the BQ25792EVM, BQ25798BKUPEVM, and BQ25798EVM.
 | WARNING: Hot surface! Contact may cause burns. Do not touch! Some components may reach high temperatures >55°C when the board is powered on. The user must not touch the board at any point during operation or immediately after operating, as high temperatures may be present. |
1 Introduction
The BQ25792 and BQ25798 (BQ25792/8) is an integrated switched-mode buck-boost battery charge management device in QFN package. It is intended to charge 1- to 4-series cell Li-ion and Li-polymer batteries. The charger features a narrow VDC architecture (NVDC) which allows the system to be regulated to a minimum value even if the battery is completely discharged. Additionally, the BQ25792/8 supports input source detection through D+ and D- which is compatible with USB2.0, USB3.0 power delivery, non-standard adapters, and high voltage adapters. With dual input source selection, USB OTG support, and an integrated 16-bit multi-channel analog-to-digital converter (ADC), the BQ25792/8 is a complete charging solution.
1.1 EVM Features
The BQ25792/8EVM is a complete module for evaluating the BQ25792/8 charger IC in the QFN package. Key features of this EVM include:
- Synchronous Switch Mode Buck-Boost Charger for 1s-4s Battery Configuration for 5-A Charging with 10-mA Resolution
- Support for 3.6-V to 24-V Wide Range of Input Sources USB Auto-Detect, USB PD and Wireless Input
- Dual Input Source Selector to Drive Bi-Directional Blocking NFETs
- Power up USB Port from Battery (USB OTG) with 2.8-V to 22-V OTG Output Voltage with 10-mV Resolution
- Low Battery Quiescent Current < 1 µA in Shutdown Mode
- BQ25798 has MPPT and backup mode features.
The device data sheet, listed in Table 1-1, provides detailed features and operation.
1.2 I/O Descriptions
Table 1-2 table lists the BQ2579XEVM board connections and ports.
| Connector, Port | Description | |
|---|---|---|
| J1 | VIN1 | Positive rail of the priority input adapter or power supply |
| GND | Ground | |
| J2 | VIN2 | Positive rail of the secondary input adapter or power supply |
| GND | Ground | |
| J3 | SYSTEM | Positive rail of the charger system output voltage, typically connected to the system load |
| GND | Ground | |
| J4 | VPMID | Positive rail of the charger output voltage for reverse mode (OTG). This output also shares the rail with VBUS in forward mode |
| GND | Ground | |
| J5 | BATTERY | Positive rail of the charger battery input |
| SNS_BATP | Input connected to the positive terminal of the battery for remote battery voltage measurement | |
| GND | Ground | |
| J6 | USB port | USB Micro B port used for input source type detection and handshaking. Connected to either VIN1 or VIN2 |
| J7 | EXTERNAL THERMISTOR | Input connected to an external battery temperature sensing thermistor |
| GND | Ground | |
| J8 | Communication port | I2C communication port for use with the EV2300/2400 Interface Board |
| J9 | Communication port | I2C communication port for use with the USB2ANY Interface Adapter (for future use) |
Table 1-3 lists the shunt installations available on the EVM, and their respective descriptions.
| Shunt | Description | BQ25792/6/8 Setting |
|---|---|---|
| JP1 | ACDRV1 pin connection to control ACFET1-RBFET1. Connect this to _acdrv1 net (labeled VAC1 FET) when utilizing the input protection MOSFETs. Connect this to GND when input protection MOSFETs are not used or bypassed | ACDRV1 to VAC1 FETs (short pins 1 to 2) |
| JP2 | ACDRV2 pin connection to control ACFET2-RBFET2. Connect this to _acdrv2 net (labeled VAC2 FET) when utilizing the input protection MOSFETs. Connect this to GND when input protection MOSFETs are not used or bypassed | ACDRV2 to VAC2 FETs (short pins 1 to 2) |
| JP3 | VIN1/VAC1 to VBUS bypass connection. Connect this when the input protection MOSFET feature is not desired. This connects the input source on VIN1 to VBUS. | Not Installed |
| JP4 | VIN2/VAC2 to VBUS bypass connection. Connect this when the input protection MOSFET feature is not desired. This connects the input source on VIN2 to VBUS. | Not Installed |
| JP5 | BAT to BATTERY bypass connection. Connect this when the ship and shutdown mode features are not desired and JP8 pins 1 and 2 are shorted. | Not Installed |
| JP6 | USB Micro B input D– connection to charger D- pin. Connect this when the input source detection and handshake features are desired. | Installed |
| JP7 | USB port J6 positive rail to charger VBUS selection. Use shunt to select either VIN1/VAC1 or VIN2/VAC2 as the connection for the USB port. | USB_VIN to VAC1 |
| JP8 | SDRV pin connection to control SFET. Short pins 1 to 2 of JP8 and install shunt across JP5 when ship and shutdown mode features are not desired. Short pins 2 to 3 of JP8 and remove shunt from JP5 when ship and shutdown mode features are desired. | Short pins 2 to 3 |
| JP9 | BATP pin connection. BATP is always connected to J5 pin 2 for remote battery sense. If off-board remote sense is not used, short pin 2 to J5 pin 1 (BATTERY) for the charger constant voltage sensing to occur at the J5 connector after the Q5 ship mode FET Short pin 2 to pin 3 (BAT pin) for the charger constant voltage sensing to occur on the PCB board close to the IC before Q5 ship mode FET. Do not leave BATP pin floating. | Short pin 2 to J5 pin 1 (BATTERY) |
| JP10 | Charger D+ and D- pin short connection. Connect this to simulate a DCP type adapter for the input source detection and handshake feature. Remove in order to use the charger's D+/D- detection feature. | Installed |
| JP11 | USB Micro B input D+ connection to charger D+ pin. Connect this when the input source detection and handshake features are desired. | Installed |
| JP12 | REGN to TS resistor divider network connection. This must remain connected. | Installed |
| JP13 | ILIM_HIZ pin setting for 500 mA. Connect to set the external input current limit setting to 500mA | Not Installed |
| JP14 | ILIM_HIZ pin setting for 1.5 A. Install shunt to set the external input current limit setting to 1.5 A. | Installed |
| JP15 | Thermistor COOL temperature setting. Connect jumper to simulate charger entering TCOOL (T1-T2) temperature region. | Not Installed |
| JP16 | Thermistor COLD temperature setting. Connect jumper to simulate charger entering TCOLD (<T1) temperature region. | Not Installed |
| JP17 | CE pin connection to ground to enable charging. When removed, CE pin will pull up to disable charge | Installed |
| JP18 | Thermistor NORMAL temperature setting. Connect jumper to simulate charger entering TNORMAL (T2-T3) temperature region. Keep connected when testing other thermistor temperature settings (JP17 - TCOOL, JP18 - TCOLD, JP21 - TWARM, JP22 - THOT). Remove this jumper whenever using an externally connected thermistor. | Installed |
| JP19 | Thermistor WARM temperature setting. Connect jumper to simulate charger entering TWARM (T3-T5) temperature region. | Not Installed |
| JP20 | Thermistor HOT temperature setting. Connect jumper to simulate charger entering THOT (>T5) temperature region. | Not Installed |
| JP21 | ILIM_HIZ pin setting for HIZ mode. Connect to enter the charger high impedance (HIZ) mode to disable the converter | Not Installed |
| JP22 | PROG pin setting for 1S, 1.5 MHz. Connect to configure charger default setting to 1S charge regulation voltage, 2 A charging current, and 1.5 MHz switching frequency | Not Installed |
| JP23 | PROG pin setting for 1S, 750 kHz. Connect to configure charger default setting to 1S charge regulation voltage, 2 A charging current, and 750 kHz switching frequency | Not Installed |
| JP24 | PROG pin setting for 2S, 1.5 MHz. Connect to configure charger default setting to 2S charge regulation voltage, 2 A charging current, and 1.5 MHz switching frequency | Installed |
| JP25 | PROG pin setting for 2S, 750 kHz. Connect to configure charger default setting to 2S charge regulation voltage, 2 A charging current, and 750 kHz switching frequency | Not Installed |
| JP26 | PROG pin setting for 3S, 1.5 MHz. Connect to configure charger default setting to 3S charge regulation voltage, 1 A charging current, and 1.5 MHz switching frequency | Not Installed |
| JP27 | PROG pin setting for 3S, 750 kHz. Connect to configure charger default setting to 3S charge regulation voltage, 1 A charging current, and 750 kHz switching frequency | Not Installed |
| JP28 | PROG pin setting for 4S, 1.5 MHz. Connect to configure charger default setting to 4S charge regulation voltage, 1 A charging current, and 1.5 MHz switching frequency | Not Installed |
| JP29 | PROG pin setting for 4S, 750 kHz. Connect to configure charger default setting to 4S charge regulation voltage, 1 A charging current, and 750 kHz switching frequency | Not Installed |
| JP30 | Input connection for onboard PULLUP rail LDO. Connect to power onboard 3.3V pullup rail. LDO input will be connected via diode-OR between VBUS and BAT | Installed |
| JP31 | EV2400 internal pullup to PULLUP connection. Connect to use EV2400 internal 3.3 V pullup to drive the EVM PULLUP rail. | Not Installed |
| JP32 | STAT pin LED indicator connection. This indicates the current charger Status | Installed |
| JP33 | USB2ANY internal pullup to PULLUP connection. Connect to use the USB2ANY internal 3.3 V pullup to drive the EVM PULLUP rail | Not Installed |
| S1 | QON control switch. Press to either exit Ship Mode or reset the System Power | Default Off |
1.3 Recommended Operating Conditions
| Description | Min | Typ | Max | Unit | |
|---|---|---|---|---|---|
| V(VINx) at J1 or J2 | Power supply voltage to the external blocking FETs which allow power to VBUS pin | 3.6 | 24 | V | |
| I(INx) into J1 or J2 | Power supply current, which can be limited by charger's input current limit feature (IINDPM) | 0.01 | 3.3 | A | |
| V(BATTERY) voltage at J5 | Battery voltage supported for precharge | 2.2 | 3.8(1S), 7.6(2S), 11.4(3S), 15.2V(4S) | 18.8 | V |
| I(BATTERY) out of/into J5 | Battery charge current | 0.01 | 2 (1S, 2S), 1(3S, 4S) | 5 | A |
| V(SYS) at J3 | System voltage regulation range | 3.2 | 19 | V | |
| I(SYS) out of J3 | System load current | 0 | 5 | A |
