The ADN8834 is a single-chip TEC controller from Analog Devices: everything needed to hold a laser diode or component at a set temperature with a thermoelectric cooler - power stage, control amplifiers and protection - in one device. ADN8834ACBZ-R7 is the RoHS-compliant ("Z") 25-ball WLCSP (CB-25-7, 2.54 mm x 2.54 mm) on tape and reel; the same die also comes in a 24-lead LFCSP.

The power stage is the signature. A TEC must be driven in both directions (cool and heat), which takes an H-bridge. The ADN8834 integrates all four MOSFETs (P-side ~47 mΩ, N-side ~31 mΩ at 5 V) and splits the bridge into a 2.0 MHz PWM half - efficient, and fast enough for a tiny inductor - and a linear half that smooths the TEC current to low ripple. The result is up to 1.5 A of clean bidirectional TEC current from a 2.7 V to 5.5 V rail without external power transistors.

The control side is equally complete: two zero-drift, rail-to-rail chopper amplifiers form the thermistor input and the PID compensation network, so the entire analog temperature loop is built around the chip with just resistors and capacitors - no external precision op amps, and microvolt-class drift where millikelvin stability is the goal. The VLIM/SD and ILIM pins set independent heating and cooling voltage/current limits (VLIM doubles as shutdown), and ITEC/VTEC outputs report the TEC's real-time current and voltage to the system.

Note: Values are taken from the Analog Devices ADN8834 datasheet. Confirm every parameter against the latest official documentation before committing a design.

ADN8834ACBZ-R7 is supplied in a 25-ball WLCSP (wafer-level chip scale package, ADI outline CB-25-7), just 2.54 mm x 2.54 mm with a 0.5 mm ball pitch - small enough to live inside an optical transceiver next to the TOSA. "Z" marks the RoHS-compliant lead-free finish and "R7" the tape-and-reel packing. The same die in a 24-lead LFCSP (ADN8834ACPZ) suits boards that prefer leaded assembly. Keep the SW-node inductor loop tight, separate PGND power returns from AGND sense ground, and place the thermistor network close to the input balls. Package dimensions and the A1-ball orientation are shown below.

📄 Full specifications are detailed in the official Analog Devices ADN8834 datasheet.

The 25-ball WLCSP (5 x 5 grid, A1-E5) groups the power bridge, the two amplifiers and the control/monitor signals:

• PVIN (C1, C2) / VDD (D5): Power-stage and controller supplies, 2.7-5.5 V.
• SW (D1, D2) + SFB (E3): PWM switch node to the inductor and its feedback; LDR (B1, B2) is the linear-side TEC drive.
• PGNDL (A1, A2) / PGNDS (E1, E2) / AGND (E4): Power and analog grounds - keep them partitioned.
• IN1P/IN1N/OUT1 (A4, B3, A3): Chopper amplifier 1 - thermistor input stage.
• IN2P/IN2N/OUT2 (A5, B4, C4): Chopper amplifier 2 - PID compensation stage.
• VLIM/SD (B5) / ILIM (C5): Independent heat/cool voltage and current limits; VLIM doubles as shutdown.
• ITEC (C3) / VTEC (D3): Real-time TEC current and voltage monitor outputs.
• EN/SY (D4) / VREF (E5): Enable with PWM sync option, and the precision reference output.

Refer to the package drawing below for the physical A1-E5 ball map of the WLCSP-25.

The parts below are related TEC controllers available in our catalog. They are not drop-in replacements; verify current rating, integrated vs external FETs, package and loop architecture before substituting.

Selection Tips: Stay with the ADN8834 for up to 1.5 A with everything integrated in the smallest footprint. The ADN8833/ADN8835 are the same family at lower/higher current; choose the ADN8831 or LTC1923 with external FETs when the TEC needs more than the integrated bridge can carry, or the MAX1978 as an alternate-vendor integrated option.

Analog Devices, Inc. (ADI), headquartered in Wilmington, Massachusetts, USA, is a global leader in high-performance analog, mixed-signal and RF semiconductors, and the dominant supplier of TEC controllers for optical communications. The ADN8834 sits in ADI's optical-module power portfolio, where the integrated PWM+linear bridge and zero-drift loop amplifiers were developed specifically for laser temperature control in tight spaces.

ADI backs the ADN8834 with full datasheet characterization, reference designs for thermistor PID loops, and application guidance on loop tuning, limit setting and WLCSP layout - the items that decide whether a laser holds its wavelength over life and temperature.