Описание
The TLV1548 is a CMOS 10-bit switched-capacitor successive-approximation (SAR) analog-to-digital (A/D) converter. The device has a chip select (CS), input-output clock (I/O CLK), data input (DATA IN) and serial data output (DATA OUT) that provides a direct 4-wire synchronous serial peripheral interface (SPI, QSPI) port of a host microprocessor. When interfacing with a TMS320 DSP, an additional frame sync signal (FS) indicates the start of a serial data frame. The device allows high-speed data transfers from the host. The INV CLK input provides further timing flexibility for the serial interface. In addition to a high-speed converter and versatile control capability, the device has an on-chip 11-channel multiplexer that can select any one of eight analog inputs or any one of three internal self-test voltages. The sample-and-hold function is automatic except for the extended sampling cycle, where the sampling cycle is started by the falling edge of asynchronous CSTART. At the end of the A/D conversion, the end-of-conversion (EOC) output goes high to indicate that the conversion is complete. The TLV1548 is designed to operate with a wide range of supply voltages with very low power consumption. The power saving feature is further enhanced with a software-programmed power-down mode and conversion rate. The converter incorporated in the device features differential high-impedance reference inputs that facilitate ratiometric conversion, scaling, and isolation of analog circuitry from logic and supply noise. A switched-capacitor design allows low-error conversion over the full operating temperature range. The TLV1548 has eight analog input channels. The TLV1548Q is characterized for operation over the full automotive temperature range of –40°C to 125°C.
