PS08 - Innovative Single-Chip Solution for Weigh Scales
Single Chip Weight Measurement Solution for Strain Gage
The PS08 single-chip solution is a high-end signal converter with a microprocessor on a single chip. The chip is designed for metal strain gauge weight measurement.
Ultra Low Power Current Consumption The PS08 is remarkable due to the very high resolution and ultra low current consumption of the total system.
Suited to Legal for Trade Scales
PS08 joins a 24-Bit microprocessor with a high resolution T/D-converter (TDC) using the PICOSTRAIN measuring principle. An LCD controller with an EEPROM make the device a full system on chip. With excellent linearity and drift numbers it can be compared with high-end A/D-converters. 80,000 divisions of stable display (internally 500,000 divisions) is possible. High resolution ( to 28 bit rms) and high stability over temperature and voltage makes the PS08 suitable in legal for trade scales up to 10,000 divisions.
Faster and More Efficient Over Traditional A/D Converter Solutions The low-power custom designed 24-Bit microprocessor has a powerful ALU. The PICOSTRAIN measuring unit reveals an impressive performance. A full system with the strain gauge may need less than 100 µA at 5,000 divisions and 5 Hz update rate due to minimal computing time. This is 10 to 20 times less than what a traditional A/D-converter solution needs. The device can be driven by a lithium coin cell for years with a 2.2V specification.
Long Battery Life - Ideal for Wireless and Solar Scales Wireless applications realize the advantage with increased battery lifetime. Taking all measure of power current savings the power current in home and office applications can be reduced to approx. 15 µA. PSØ8 is therefore the first device worldwide that allows the making of solar scales with strain gauges.
Please Note: The PS08 is not recommended for new designs, please see the PS081 and PS09.
PS08 - Circuit Features - For Digital Strain Gage
Trigger to rising and/or falling edge
PICOSTRAIN Front-End with up to 19 Bit resolution (@2mV/V)
Capability to measure half-bridges, full-bridges, quattro-bridges and Wheatstone-bridges
Microprocessor with 24-Bit data structure
1 k x 8-Bit EEprom progam memory including charge pump (no need of an additional programming voltage)
3 k ROM powerful program code - 48 Bit multiplication and division or binary to 7-segment conversion
8-layer hardware stack
Embedded very low current 10 kHz oscillator (300 nA)
Driver for external 4 MHz ceramic oscillator
Operating current 0.7 µA with timer active
5 programmable I/O-ports
4 x 14, 3 x 15, 2 x 16 LCD driver
Embedded charge pump for driving the LCD at 2.0 V, 2.5 V and 3.0 V
Embedded bandgap voltage reference for low battery detection and LCD voltage stabilization
Ports for temperature measurement with low-cost external carbon resistors
Watchdog timer
Serial SPI interface for EEPROM programming or operation with an external microprocessor
Supply voltage 2.2 to 3.6 V (full functionality) - 1.5 V (without EEPROM reprogramming and voltage measurement)
System operational current down to 15 µA at 3 Hz and 2000 divisions
