Linear Technology releases high-voltage amplifier

Linear Technology has launched the LT1999, a high-voltage amplifier designed to provide bidirectional current sensing in the presence of fast switching common-mode voltages from -5V to +80V.

This wide-input common-mode range is obtained with standard low-voltage operational amplifier supplies.

A 2MHz bandwidth enables the LT1999 to monitor currents in H-bridge motor controls, switching power supplies and solenoid and battery chargers.

To maintain accuracy, even when monitoring motor and solenoid current, the LT1999 ensures more than 80dB of common-mode rejection at 100kHz.

This ensures that the amplifier remains insensitive to the large square wave input common-mode voltages present in these applications.

The LT1999 features a buffered output with three fixed-gain options for 10V/V, 20V/V and 50V/V.

By default, the LT1999 output voltage is referenced half way between the supply voltage and ground, enabling the output to indicate both the magnitude and direction of the sensed current.

In addition, the output bias level can be set via a separate input.

According to the company, gain error is guaranteed at less than 0.5 per cent and input offset voltage is ensured at less than 1.5mV over the full temperature range of -40C to +125C.

The LT1999 operates with an independent 5V supply voltage, drawing only 1.5mA while active and just 10uA in shutdown mode.

Offered in an eight-lead MSOP package and an eight-lead SOP package, the LT1999 range is fully specified over four temperature ranges: 0C to +70C, -40C to +85C, -40C to +125C and -55C to +150C.

The LT1999 is in full production, with prices starting at USD1.92 (GBP1.17) each in 1,000-piece quantities.

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