1 Features
• ±50-V operating voltage, ±55-V absolute maximum
• Integrated fixed bipolar 32-mA current limit
• Allows 2x current limit at start-up
• 50% space savings compared to a typical discrete
protection circuit
• Low R-on: 7.5-Ω typical
• Low IQ (< 100 nA) – current drawn from loop when
powered from external supply
• Protection against miswiring conditions on IN and
OUT
• Protection during signal line surge IEC61000-4-5
(with external TVS)
• Criteria-A EFT (IEC61000-4-4) immunity (with
external TVS)
• Supports loop testing without supply (TPS26610
only)
• HART compliant
• Enable control
• SGOOD for system health monitoring
• Thermal shutdown

2 Applications
• Factory automation and control – PLCs - analog
input and output module
• Motor drives control
• HART inputs
• HVAC controllers
• UART IO protection
• Thermal controller

3 Description
The TPS2661x is a compact, feature-rich, fully
integrated current loop protector suitable for analog
inputs, analog outputs, sensor transmitters, HART
inputs, and UART IO protection. The device provides
universal input protection for ±20 mA, 0 mA to 20 mA,
and 4 mA–20 mA. Low RON values of 7.5 Ω minimizes
drop in the current loop, thereby extending operating
range and supporting operation even with lower
voltage power supplies. The device can withstand and
protect the loads from positive and negative supply
voltages up to ±50 V. The MODE pin allows flexibility
to enable 2x current limit through the device to enable
proper start-up of two wire transmitters. Device is
capable of operating from an external bipolar supply
as low as ± 2.25 V to ±20 V. The device can also
be powered from unipolar supplies as low as 3 V
to 30 V. The TPS26610 and TPS26613 feature loop
power mode to facilitate loop testing in un-powered
state without ±Vs supplies.
The device also protects the system from output side
miswiring in analog outputs and sensor transmitters
by turning off the current path. The internal robust
protection control blocks along with the 50-V rating
of the TPS2661x help to protect against surge
(IEC61000-4-5) and EFT (IEC61000-4-4) transients
for signal lines. The device greatly reduces system
footprint by its 2.9-mm × 1.6-mm 8-pin SOT-23
package.