TM7705

TM7705 is a 2/3-channel analog front end for low-frequency measurement applications. The device accepts low-level input signals directly from sensors and produces a serial digital output. 16-bit no missing code performance is achieved using Σ-Δ conversion technology. The selected input signal is routed to a gain-programmable dedicated front end based on an analog modulator. An on-chip digital filter processes the modulator output. The filter cutoff point and output update rate are adjustable via on-chip control registers, enabling programming of the first notch of the digital filter. The TM7705 requires only a 2.7~3.3V or 4.75~5.25V single supply. The TM7705 features dual fully differential analog inputs with one differential reference input. With a 5V supply and 2.5V reference, the device can process input signal ranges from 0~+20mV to 0~+2.5V. It can also handle bipolar input signals from ±20mV to ±2.5V, referenced to the AIN(−) input on the TM7705. With a 3V supply and 1.225V reference, it can process unipolar input signals from 0~+10mV to 0~+1.225V, with a bipolar input range of ±70mV to ±1.225V. The TM7705 therefore provides complete signal conditioning and conversion for all signals in a 2/3-channel system. The TM7705 is an ideal solution for intelligent systems, microcontroller-based systems, and DSP-based systems. Its serial interface can be configured as a 3-wire interface. Gain, signal polarity, and update rate selections are configurable via the serial input port in software. The device also includes self-calibration and system calibration options to eliminate gain and offset errors from the device itself or the system. The CMOS architecture ensures extremely low power consumption, with power-down mode reducing standby power dissipation to 20μA (typical). The TM7705 is available in 16-pin plastic DIP, 16-pin wide-body (0.3-inch) SOIC, 16-pin TSSOP, 16-pin SOP, and 16-pin SSOP packages.

Applications

• Intelligent Systems
• Microcontroller Systems
• DSP-Based Systems

Key features

• 16-bit, no missing codes, 0.003% nonlinearity ADC with 2 fully differential input channels and programmable gain front end
• Gain: 1~128
• 3-wire serial interface
• Analog input buffering capability
• 2.7~3.3V or 4.75~5.25V supply voltage; max power dissipation 1mW at 3V
• Max standby current: 8μA
• 16-pin DIP, SOIC (wide body), TSSOP, SOP, and SSOP packages