The MAX4936–MAX4939 are octal, high-voltage, transmit/receive (T/R) switches. The T/R switches are based on a diode bridge topology, and the amount of current in the diode bridges can be programmed through an SPIK interface. All devices feature a latch-clear input to asynchronously turn off all T/R switches and put the device into a low-power shutdown mode. The MAX4936/MAX4938 include the T/R switch and grass-clipping diodes, performing both transmit and receive operations. The MAX4937/MAX4939 include just the T/R switch and perform the receive operation only. The MAX4936/MAX4938 transmit path is low impedance during high-voltage transmit and high impedance during low-voltage receive, providing isolation between transmit and receive circuitry. The high-voltage transmit path is high bandwidth, low distortion, and low jitter. The receive path for all devices is low impedance during low-voltage receive and high impedance during high-voltage transmit, providing protection to the receive circuitry. The low-voltage receive path is high bandwidth, low noise, low distortion, and low jitter.
The MAX4936‑MAX4939 family provides eight high‑voltage transmit/receive (T/R) switches per package, each programmable via an SPIK interface. The devices feature low‑impedance operation during transmit, high‑impedance isolation during receive, and a global shutdown (CLR) pin for low‑power mode.
These switches are offered in a compact 56‑pin, 5 mm × 11 mm TQFN package and operate over a commercial temperature range (0 °C to +70 °C). Typical applications include medical ultrasound systems and other high‑voltage signal‑routing designs.
| Supply Voltage (VDD) | -0.3 V to +6 V |
|---|---|
| Package | 56‑pin 5 mm × 11 mm TQFN |
| Number of Channels | 8 per package |
| Bandwidth (‑3 dB) | 65 MHz (typ) |
| Low‑Power Mode | Low Impedance (5 Ω) with 1.5 mA bias |
| Shutdown Control | Global CLR pin |
The switches are programmed through an SPIK (SPI) interface.
Each package contains eight independent transmit/receive channels.
The CLR pin provides a global shutdown control for all switches.