ZMDI公司的ZSSC1856是集成了嵌入式MCU的双路高精度18位Sigma-Delta ADC,其中的一路输入通过外接电阻测量电池电流IBAT(失调误差小于10mA,分辨率优于1mA),另一路测量电池电压VBAT(输入范围4-28.8V,精度+/-2mV)和温度,而集成的闪存则用来计算电池的状态.可编增益4-512,取样速率1Hz到16kHz,主要用在汽车,工业和医疗领域.本文介绍了ZSSC1856主要特性和优势,方框图,基本应用电路和典型应用电路.
The ZSSC1856 is a dual-channel ADC with an embedded microcontroller for battery sensing/management in automotive, industrial, and medical systems.
One of the two input channels measures the battery current IBAT via the voltage drop at the external shunt resistor. The second channel measures the battery voltage VBAT and the temperature. An integrated flash memory is provided for customer-specific soft-ware; e.g., dedicated algorithms for calculating the battery state.
During Sleep Mode (e.g., engine off), the system makes periodic measurements to monitor the dis-charge of the battery. Measurement cycles are controlled by the software and include various wake-up conditions. The ZSSC1856 is optimized for ultra-low power consumption and draws only 100μA or less in this mode.
The ZSSC1856 consists of two silicon dies in one package. The dies are assembled as stacked dies in a PQFN32 5x5mm package. The System Basis Chip (SBC) contains the high voltage circuits, the analog input stage including peripheral blocks, the ΣΔ-ADCs, the digital filtering, and the LIN-transceiver. The microcontroller chip (MCU) contains the microcontroller core, memories, and some peripheral blocks. Communication between the MCU and the SBC is handled by an SPI interface. Internal nodes connecting the MCU and the SBC (i.e., TXD, RXD, IRQN, CSN, SPI_CLK, MOSI, MISO, MCU_CLK, MCU_RSTN, and RAM_PROTN) are controlled by firmware. Users can access the internal nodes via the LIN interface and/or external JTAG pins (i.e., TDO, TDI, TRSTN, TMS, and TCK).  

ZSSC1856主要特性:
 High-precision 18-bit sigma-delta ADC with on-chip voltage reference (5ppm/K)
 Current channel
IBAT offset error: ≤ 10mA
IBAT resolution: ≤ 1mA
Programmable gain: 4 to 512
Differential input stage input range: ± 300mV
Sampling rate: 1Hz to 16kHz
 Voltage channel 
 Input range: 4 to 28.8V
 Voltage accuracy: ± 2mV
 Temperature channel 
 Internal temperature sensor: ± 2℃ 
 External temperature sensor (NTC)
 On-chip precision oscillator (1%)
 On-chip low-power oscillator
 ARM® Cortex™-M0* microcontroller: 32-bit core, 10MHz to 20MHz
 96kB Flash/EE Memory with ECC, 8kB SRAM
 LIN2.1 / SAE J2602-1 Transceiver
 Directly connected to 12V battery supply
 Current consumption
Normal Mode: 10mA to 20mA
Low-Power Mode: ≤ 100μA

ZSSC1856优势:
 Integrated, precision measurement solution for accurate prediction of battery state of health (SOH), state of charge (SOC) or state of function (SOF)
 Flexible wake-up modes allow minimum power consumption without sacrificing performance
 No temperature calibration or external trimming components required
 Optimized code density through small instruction set architecture Thumb®-2 *
 Robust POR concept for harsh automotive environments
 Industry’s smallest footprint allows minimal module size and cost
 AEC-Q100 qualified solution

ZSSC1856应用:
 Intelligent battery sensing for automotive applications; e.g., start/stop systems, e-bikes, scooters, and e-carts
 Industrial and medical applica-tions requiring precise battery SOC, SOH and SOF monitoring; e.g., emergency lighting, uninter-ruptable power supplies, hospital equipment, alarm systems, and more

图1.ZSSC1856方框图

图2.ZSSC1856系统基本芯片(SBC)数字部分方框图

图3.ZSSC1856 MCU部分方框图

图4.ZSSC1856模拟测量子系统功能方框图

图5.ZSSC1856基本应用电路图

图6.ZSSC1856典型应用电路图