The XTR11x low compliance voltage rating (7.5 V) permits the use of various voltage protection methods without compromising the operating range. Figure 7-2 shows a diode bridge circuit that allows normal operation even when the voltage connection lines are reversed. The bridge causes a two-diode drop (approximately 1.4 V) loss in loop supply voltage. This loss results in a compliance voltage of approximately 9 V—satisfactory for most applications. A diode can be inserted in series with the loop supply voltage and the V+ pin to protect against reverse output connection lines with only a 0.7-V loss in loop supply voltage.

(1) Zener Diode 36 V: 1N4753A or Motorola P6KE39A. Use lower-voltage Zener diodes with loop power-supply voltages less than 30 V for increased protection; see Section 7.3.2.

Figure 7-2 Reverse Voltage Operation and Overvoltage Surge Protection