COSINE Tier-1 distributor Jarwey｜36V precision op amp slew rate: COS1177SR at 0.7 V/µs vs COS227USR and COS228USR

Jarwey is a COSINE Tier-1 distributor and can help with the shortlist, the datasheet, samples, small lots, and lead time.

The 36V precision op amps are already split by channel count at 2 MHz, 10 MHz, and 25 MHz. A larger GBP does not buy a lower offset. COS1177SR, COS227USR, and COS228USR are all 50 µV max and 0.2 µV/°C in the 2025 catalog. What changes is slew rate, quiescent current, and the listed input bias current.

Set the output amplitude first. Slew rate decides whether a large sine or a large step survives. GBP is the small-signal budget, and only after the datasheet shows the stable noise gain. The table uses one single-channel SOP-8 per row. Dual and quad parts share that row; the channel matrices stay in the earlier family notes.

Same offset, three slew rates

Figures are the COSINE 2025 catalog rows for 36V precision op amps. The catalog does not mark input bias as typical or maximum. Treat the bias column as a catalog listing until Jarwey sends the datasheet.

The sine limit is f ≈ SR / (2π × Vp). It is an estimate of where slew rate runs out, not a catalog full-power bandwidth. At 0.7 V/µs and 10 V peak, 0.7×10⁶ / (2π×10) is about 11.1 kHz. Drop the peak to 1 V and the same amplifier estimates about 111 kHz. Leave Vp off the requisition and the MHz row is a guess.

Catalog noise density is 8 / 6 / 5.0 nV/√Hz at 1 kHz. That is a small step next to quiescent current: 0.33 mA versus 2.6 mA, about eight times, if the 25 MHz row is chosen only for margin.

Bias current on a high-Z sensor

Listed Ib is 1 nA, 5 nA, and 10 nA. Across 100 kΩ that is about 0.1 mV, 0.5 mV, and 1.0 mV. Use it as a scale check, not a guaranteed error. A slow, high-impedance sensor often stays cleaner on COS1177SR than on COS228USR. A low-impedance node that must follow a fast, large step is the reason to look at 3.0 V/µs or 10 V/µs.

Supply range is 4.5–36 V (±2.25 to ±18 V) on all three rows, so a ±15 V rail can sit here. The catalog does not call the input range rail-to-rail. Confirm common-mode and output headroom on the datasheet.

OP1177, OPA227, and OPA228 are search anchors only. They need a board-level check. They are not a drop-in claim. Do not divide GBP by noise gain until the datasheet shows the gain at which the amplifier is stable.

Channel count is a separate note

Duals and quads with the same electrical row are already published: the 2 MHz family (COS2177SR / COS4177SR), the 10 MHz family (COS2227USR / COS4227UATR), and the 25 MHz family (COS2228USR / COS4228UATR). Pick the slew-rate row, then the channel count.

Checklist

1. Peak output: write Vp for the sine or the step, not only “36 V op amp”.
2. Slew ceiling: SR / (2πVp). At 10 V peak the 0.7 / 3.0 / 10 V/µs rows land near 11 kHz, 48 kHz, and 159 kHz.
3. Offset is not the upgrade: all three rows are 50 µV and 0.2 µV/°C.
4. Current: Iq is 0.33 / 1.3 / 2.6 mA. Listed Ib is 1 / 5 / 10 nA. Estimate the error on a high-Z source before moving up.
5. Small-signal bandwidth: use 2 / 10 / 25 MHz GBP only after the datasheet fixes noise gain and stability.
6. Package: single SOP-8 parts are COS1177SR, COS227USR, and COS228USR. Dual and quad stay on the family pages.
7. Sample: ask Jarwey for the datasheet, then measure slew and settling on the real load before the production PN is locked.

Product pages

• COS1177SR · 2 MHz · 0.7 V/µs · SOP-8
• COS227USR · 10 MHz · 3.0 V/µs · SOP-8
• COS228USR · 25 MHz · 10 V/µs · SOP-8

Send output amplitude, the highest signal frequency, and source impedance to Jarwey: kerry.w@jarwey.cn · Contact.