STMicroelectronics OA1MPA22C

Overview

OA1MPA22C from STMicroelectronics is a single-channel, rail-to-rail input/output, high-precision CMOS operational amplifier optimized for ultra-low-power, low-voltage battery operation. It delivers 200 µV max input offset voltage, 10 µA supply current at 5 V, 1.5–5.5 V supply range, and 150 kHz gain bandwidth product - enabling precision signal conditioning in space-constrained wearable and medical sensor front-ends.

For engineers reviewing the OA1MPA22C datasheet, OA1MPA22C pinout, OA1MPA22C application, or OA1MPA22C equivalent, this device is selected for sub-2 V operation, EMI-hardened analog sensing, long-term offset stability (≤0.7 µV/month), and guaranteed performance across –40 °C to +125 °C industrial temperature range.

Technical Context

The OA1MPA22C employs ST's proprietary 5 V CMOS process with on-chip trimming to achieve <200 µV initial offset and <10 µV/°C drift over –40 °C to +125 °C. Its rail-to-rail input stage uses complementary differential pairs extending common-mode range to V_CC±0.1 V, while the output stage supports 40 mV high-side and 75 mV low-side headroom into 10 kΩ.

EMI hardening is implemented at transistor layout level, yielding 38–63 dB rejection across 400–2400 MHz RF bands. The device features a dedicated initialization phase post-power-up (5 ms typical at 25 °C) that re-trims offset before entering stable operation - critical for zero-drift-critical medical measurements.

Key Specifications

Pinout & Package

OA1MPA22C is housed in SC70-5 package (2.0 mm × 1.25 mm × 0.95 mm height), optimized for ultra-compact PCB layouts in wearable electronics.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision, low-power op amp applications.

Compared with TLC2271CDR and MAX44260ASA+, OA1MPA22C uniquely balances sub-200 µV offset, single-digit µA consumption, full industrial temperature range, and documented 2.4 GHz EMI rejection - making it the only choice for certified Class II wearable medical electronics requiring long-term stability and coexistence with wireless radios.

Availability

OA1MPA22C is available at Aetrix Electronics and suitable for wearable health monitors, fitness trackers, and industrial temperature sensor nodes requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for OA1MPA22C includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

OA1MPA22C belongs to ST's OAxMPA precision op amp family, engineered specifically for battery-powered medical and fitness devices demanding rail-to-rail operation, nanoamp quiescent current, and robust EMI performance in miniaturized form factors.

FAQ

What is the maximum capacitive load the OA1MPA22C can drive while maintaining stability?

The OA1MPA22C is unity-gain stable up to 100 pF capacitive load when configured with 10 kΩ feedback and load resistors, as verified in Figure 13 of the datasheet. Driving >100 pF requires isolation resistor (≥100 Ω) between output and capacitance to prevent peaking or oscillation - critical for driving ADC input filters or long PCB traces in portable designs.

Does OA1MPA22C require external calibration for medical-grade accuracy?

No. With 200 µV max input offset voltage and <10 µV/°C drift over –40 °C to +125 °C, OA1MPA22C achieves medical-grade DC accuracy without system-level trimming. Its on-chip initialization phase recalibrates offset at each power-up, eliminating need for external auto-zero circuitry in ECG or glucose biosensors.

How does the SC70-5 package affect thermal performance in sealed wearable enclosures?

The SC70-5 package has R_thJA = 205 °C/W, limiting continuous dissipation to ~1.2 mW at 60 °C ambient rise. In sealed enclosures, this restricts use to <10 µA operation - fully aligned with OA1MPA22C's 10 µA typical ICC. No heatsinking is needed, but PCB copper pour under the exposed pad (if present) is not applicable - SC70-5 has no thermal pad.

Can OA1MPA22C operate reliably from a 1.5 V alkaline battery throughout its discharge curve?

Yes. OA1MPA22C is fully specified down to 1.5 V supply, with functional operation confirmed at 1.5 V in Figures 2, 8, and 11 of the datasheet. At 1.5 V, GBP drops to 100 kHz and output swing remains rail-to-rail, supporting uninterrupted operation from fresh (1.6 V) to end-of-life (1.0 V) alkaline cells when paired with low-dropout regulators or direct battery interface.