BQ25792 是一款完全集成的开关模式降压/升压充电器,适用于 1-4 节锂离子电池和锂聚合物电池。该集成包括 4 开关 MOSFET(Q1、Q2、Q3、Q4)、输入和充电电流检测电路、电池 FET (QBAT) 以及降压/升压转换器的环路补偿。它使用 NVDC 电源路径管理,将系统电压调节至稍高于电池电压的水平,但是不会下降至低于可配置的最小系统电压。当系统功率超过输入源额定值时,电池补充模式支持系统,不会使输入源过载。BQ25792 支持 USB Type-C™ 和 USB 供电 (USB-PD) 应用的完整输入和输出 (OTG) 电压范围。
器件型号 | 封装(1) | 封装尺寸(标称值) |
---|---|---|
BQ25792 | QFN (29) | 4.0mm x 4.0mm |
Changes from Revision B (March 2021) to Revision C (August 2022)
Changes from Revision A (November 2020) to Revision B (March 2021)
充电器支持窄范围 VDC 电源路径管理,将系统电压调节至稍高于电池电压的水平,但是不会下降至低于最小系统电压。即使电池完全放电或移除,最低系统电压也允许系统运行。当系统功率超过输入源额定值时,电池补充模式支持系统电源需求,不会使输入源过载。
该器件从传统 USB 适配器到高电压 USB PD 适配器和传统桶形适配器等各种输入源为电池充电。在没有主机控制时,充电器基于输入电压和电池电压自动将转换器设置为降压、升压或降压-升压配置。双输入源选择器管理来自两个不同输入源的电源流入。输入选择由主机通过 I2C 来控制,默认源 1 (VAC1) 作为主输入,源 2 (VAC2) 作为辅助输入。
为支持通过可调节高电压适配器进行快速充电,该器件提供了 D+/D- 握手机制。该器件符合 USB 2.0 和 USB 3.0 功率传输规范,具有输入电流和电压调节功能。此外,输入电流优化器 (ICO) 还能够检测未知输入源的最大功率点。
除了 I2C 主机控制的充电模式,此充电器还支持自动充电模式。上电之后,使用默认寄存器设置启用充电。此器件可以在无需软件参与的情况下完成充电周期。它检测电池电压并在不同阶段为电池充电:涓流充电、预充电、恒定电流 (CC) 充电和恒定电压 (CV) 充电。在充电周期的末尾,当充电电流低于在恒定电压阶段中预设定的限值(终止电流)时,充电器自动终止。当整个电池下降到低于再充电阈值时,充电器将自动启动另一个充电周期。
在没有输入源的情况下,此器件支持 USB On-the-Go (OTG) 功能,对电池进行放电以在 VBUS 上以 10mV 步长产生可调的 2.8V 至 22V 电压,符合 USB PD 3.0 规范定义的可编程电源 (PPS) 特性。
该充电器提供针对电池充电和系统运行的多种安全特性,其中包括电池负温度系数热敏电阻监视、涓流充电、预充电和快速充电计时器以及电池和输入上的过压/过流保护。当结温超过可编程的阈值时,热调节会减小充电电流。器件的 STAT 输出报告充电状态和任何故障状况。当发生故障时,INT 引脚会立即通知主机。
该器件还提供了一个 16 位模数转换器 (ADC),用于监视充电电流和输入/电池/系统(VAC、VBUS、BAT、SYS、TS)电压。
它采用 29 引脚 4mm × 4mm QFN 封装。
PART NUMBER | BQ25790 | BQ25792 | BQ25798 |
---|---|---|---|
ACOVP Default Value | 7V | 26V | 26V |
ACOVP Options | 7V, 12V, 18V or 26V | 7V, 12V, 22V or 26V | 7V, 12V, 22V or 26V |
/PG pin | Yes | No | No |
IBAT pin | Yes | No | No |
BATN pin | Yes | No | No |
MPPT | No | No | Yes |
Backup Mode | No | No | Yes |
Package | DSBGA 56, 2.9mm x 3.3mm | QFN 29, 4mm x 4mm | QFN 29, 4mm x 4mm |
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
STAT | 1 | DO | Open Drain Charge Status Output – It indicates various charger operations. Connect to the pull up rail via a 10kΩ resistor. LOW indicates charging in progress. HIGH indicates charging completed or charging disabled. When any fault condition occurs, STAT pin blinks at 1Hz. The STAT pin function can be disabled when DIS_STAT bit is set to 1. |
VBUS | 2-3 | P | Charger Input Voltage – The power input terminal of the charger. An input current sensing circuit is connected between VBUS and PMID. The recommended capacitors at VBUS are 2 pieces of 10μF and one piece of 0.1μF ceramic capacitors. Place the 0.1μF ceramic capacitor as close as possible to the charger IC. |
BTST1 | 4 | P | Input High Side Power MOSFET Gate Driver Power Supply – Connect a 10V or higher rating, 47nF ceramic capacitor between SW1 and BTST1 as the bootstrap capacitor for driving high side switching MOSFET (Q1). |
REGN | 5 | P | The Charger Internal Linear Regulator Output – It is supplied from either VBUS or BAT dependent on which voltage is higher. Connect a 10V, 4.7μF ceramic capacitor from REGN to power ground. The REGN LDO output is used for the internal MOSFETs gate driving voltage and the voltage bias for TS pin resistor divider. |
D+ | 6 | AIO | Positive Line of the USB Data Line Pair – D+/D- based USB host/charging port detection for VIN1 input. The detection includes data contact detection (DCD), primary and secondary detection in BC1.2, and the adjustable high voltage adapter. |
D- | 7 | AIO | Negative Line of the USB Data Line Pair – D+/D- based USB host/charging port detection for VIN1 input. The detection includes data contact detection (DCD), primary and secondary detection in BC1.2, and the adjustable high voltage adapter. |
VAC2 | 8 | P | VAC2 Input Detection – When a voltage between 3.6V and 24V is applied on VAC2, it represents a valid input being plugged into port #2. Connect to VBUS if the ACFET2 and RBFET2 are not installed. |
VAC1 | 9 | P | VAC1 Input Detection – When a voltage between 3.6V and 24V is applied on VAC1, it represents a valid input being plugged into port #1. Connect to VBUS if the ACFET1 and RBFET1 are not installed. |
ACDRV2 | 10 | P | Input FETs Driver Pin 2 – The charge pump output to drive the port #2 input N-channel MOSFET (ACFET2) and the reverse blocking N-channel MOSFET (RBFET2). The charger turns on the back-to-back MOSFETs by increasing the ACDRV2 voltage 5V above the common source connection of the ACFET2 and RBFET2 when the turn-on condition is met. Tie ACDRV2 to GND if no ACFET2 and RBFET2 installed. |
ACDRV1 | 11 | P | Input FETs Driver Pin 1 – The charge pump output to drive the port #1 input N-channel MOSFET (ACFET1) and the reverse blocking N-channel MOSFET (RBFET1). The charger turns on the back-to-back MOSFETs by increasing the ACDRV1 voltage 5V above the common source connection of the ACFET1 and RBFET1 when the turn-on condition is met. Tie ACDRV1 to GND if no ACFET1 and RBFET1 installed. |
QON | 12 | DI | Ship FET Enable or System Power Reset Control Input – When the device is in ship mode or in the shutdown mode, the SDRV turns off the external ship FET to minimize the battery leakage current. A logic low on this pin with tSM_EXIT duration turns on ship FET to force the device to exit the ship mode. A logic low on this pin with tRST duration resets system power by turning off the ship FET for tRST_SFET (also setting the charger in HIZ mode when VBUS is high) and then turning on ship FET (also disabling the charger HIZ mode) to provide full system power reset. During tRST_SFET when the ship FET is off, the charger applies a 30mA discharging current on SYS to discharge system voltage. The pin contains an internal pull-up through a RQON resistor. The typical output voltage is 3.6 V-3.8 V with VBUS and VBAT > 5V. |
CE | 13 | DI | Active Low Charge Enable Pin – Battery charging is enabled when EN_CHG bit is 1 and CE pin is LOW. CE pin must be pulled HIGH or LOW, do not leave floating. |
SCL | 14 | DI | I2C Interface Clock – Connect SCL to the logic rail through a 10 kΩ resistor. |
SDA | 15 | DIO | I2C Interface Data – Connect SDA to the logic rail through a 10 kΩ resistor. |
TS | 16 | AI | Temperature Qualification Voltage Input – Connect a negative temperature coefficient thermistor. Program temperature window with a resistor divider from REGN to TS to GND. Charge suspends when TS pin voltage is out of range. Recommend a 103AT-2 10kΩ thermistor. |
ILIM_HIZ | 17 | AI | Input Current Limit Setting and HIZ Mode Control Pin – Program ILIM_HIZ voltage by connecting a resistor divider from pull up rail to ILIM_HIZ pin to ground. The pin voltage is calculated as: VILIM_HIZ = 1V + 800mΩ × IINDPM, in which IINDPM is the target input current. The input current limit used by the charger is the lower setting of ILIM_HIZ pin and the IINDPM register. When the pin voltage is below 0.75V, the buck-boost converter enters non-switching mode, similar to HiZ mode using EN_HIZ bit, but with REGN on. When the pin voltage is above 1V, the converter resumes switching. Connect ILIM_HIZ to REGN to set the maximum input current limit. |
BATP | 18 | P | Positive Input for Battery Voltage Sensing – Connect to the positive terminal of battery pack. Place 100Ω series resistance between this pin and the battery positive terminal. |
BTST2 | 19 | P | Output High Side Power MOSFET Gate Driver Power Supply – Connect a 10V or higher rating, 47nF ceramic capacitor between SW2 and BTST2 as the bootstrap capacitor for driving high side switching MOSFET (Q4). |
PROG | 20 | AI | Charger POR Default Settings Program – At power up, the charger detects the resistance tied to PROG pin to determine the default switching frequency and the default battery charging profile. The surface mount resistor with ±1% or ±2% tolerance is recommended. Please refer to more details in the section of PROG Pin Configuration. |
INT | 21 | DO | Open Drain Interrupt Output. – Connect the INT pin to a logic rail via a 10kΩ resistor. The INT pin sends an active low, 256μs pulse to the host to report the charger device status and faults. |
BAT | 22-23 | P | The Battery Charging Power Connection – Connect to the positive terminal of the battery pack. The internal charging current sensing circuit is connected between SYS and BAT. The recommended capacitors at BAT are 2 pieces of 10μF ceramic capacitors. |
SDRV | 24 | P | External N-channel Ship FET (SFET) Gate Driver Output – The driver pin of the external ship FET. The ship FET is always turned on when the ship mode is disabled, and it keeps off when the charger is in ship mode or shutdown mode. Connect a 1nF, 50V rated, 0402 package, ceramic capacitor from SDRV to GND or SDRV to BAT when the ship FET is not used. |
SYS | 25 | P | The Charger Output Voltage to System – The internal N-channel high side MOSFET (Q4) is connected between SYS and SW2 with drain on SYS and source on SW2. The recommended capacitors at SYS are 5 pieces of 10μF and one piece of 0.1μF ceramic capacitors. Place the 0.1μF ceramic capacitor as close as possible to the charger IC. |
SW2 | 26 | P | Boost Side Half Bridge Switching Node Inductor connection to mid point of Q3 and Q4 switches. |
GND | 27 | P | Ground Return |
SW1 | 28 | P | Buck Side Half Bridge Switching Node Inductor connection to mid point of Q1 and Q2 switches. |
PMID | 29 | P | Q1 MOSFET Drain Connection – An internal N-channel high side MOSFET (Q1) is connected between PMID and SW1 with drain on PMID and source on SW1. The recommended capacitors at PMID are 3 pieces of 10μF and one piece of 0.1μF ceramic capacitors. Place the 0.1μF ceramic capacitor as close as possible to the charger IC. |
MIN | MAX | UNIT | ||
---|---|---|---|---|
Voltage range (with respect to GND) | VAC1, VAC2 | -2 | 30 | V |
VBUS (converter not switching) | -2 | 30 | V | |
PMID (converter not switching) | -0.3 | 30 | V | |
ACDRV1, ACDRV2, BTST1 | -0.3 | 32 | V | |
SYS (converter not switching) | -0.3 | 23 | V | |
BATP, BAT | -0.3 | 20 | V | |
BTST2 | -0.3 | 29 | V | |
SDRV | -0.3 | 26 | V | |
SW1 | -2 (50ns) | 30 | V | |
SW2 | -2 (50ns) | 23 | V | |
QON, D+, D-, CE, STAT, SCL, SDA, INT, ILIM_HIZ, PROG, TS, REGN | -0.3 | 6 | V | |
Output Sink Current | INT, STAT | 6 | mA | |
Differential Voltage | BTST1-SW1, BTST2-SW2 | -0.3 | 6 | V |
PMID-VBUS | -0.3 | 6 | V | |
SYS-BAT | -0.3 | 16 | V | |
SDRV-BAT | -0.3 | 6 | V | |
TJ | Junction temperature | -40 | 150 | °C |
Tstg | Storage temperature | -55 | 150 | °C |