TS7221BILT - Single BiCMOS R2R uPower Comparator | STMicroelectronics
MPN: TS7221BILT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.95 | $1.95 |
| 10 | $1.62 | $16.20 |
| 100 | $1.18 | $118.00 |
| 500 | $0.92 | $460.00 |
| 1,000 | $0.78 | $780.00 |
TS7221BILT Overview
A comparator is an analog building block that compares two input voltages and produces a logic-level output indicating which is larger. Micropower comparators like the TS7221 occupy a position in the power-management/analog signal-chain hierarchy below op-amps but above simple logic gates, and are favoured for always-on battery-powered designs where quiescent current dominates total energy consumption. Within ST's broader comparator family, the TS7221 sits alongside the TS7222 (dual) and TS7223 (quad) as the single-channel foundation of the series.
Key features include rail-to-rail input common-mode range, an open-drain output that allows wired-OR logic and level-shifting to any pull-up voltage, very low supply current typically well under 10 uA, and 5 V/10 V operation suitable for industrial sensor interfaces. The BiCMOS process combines CMOS input stages with bipolar output drive for a balance of low power and reasonable switching speed. Internal ESD protection on the inputs (HBM 2000 V per the datasheet absolute maximum ratings) further improves robustness in handheld and field-deployed equipment.
Typical applications include battery-pack voltage monitoring, threshold detectors, window comparators, and signal conditioning in IoT sensor nodes, wearables, and portable medical devices. The small SOT-23-5 footprint also makes the device attractive for space-constrained designs such as hearing aids and remote keyless-entry keyfobs. When designing with this part, choose the pull-up resistor on the open-drain output based on the desired propagation delay versus power budget; lower pull-up resistance speeds up edges but increases static current when the output is LOW.
Drop-in alternatives for TS7221BILT — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TS7221AILT
✅ Drop-In📋 Reference alternative (not in catalog)
TS7221BIL
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LMV331M7
✅ Drop-In📋 Reference alternative (not in catalog)
TS7221BILT-TR
✅ Drop-In📋 Reference alternative (not in catalog)
LPV7215M5
✅ Drop-In📋 Reference alternative (not in catalog)
TS7221BILT Maximum Ratings & Electrical Characteristics
| Comparator Type | General Purpose, Micropower |
| Number of Channels | 1 |
| Output Type | Open-Drain |
| Input Common-Mode Range | Rail-to-Rail |
| Supply Voltage (Single) | 2.7 V to 10 V |
| Specified Operation Voltages | 2.7 V, 5 V, 10 V |
| ESD Protection (HBM) | 2000 V |
| ESD Protection (MM) | 200 V |
| Operating Temperature Range | -40C to +85C |
| Package | SOT-23-5 |
| Mounting Type | Surface Mount |
| Grade Suffix | B (tighter Vio), I (industrial temp), LT (tape & reel) |
TS7221BILT Pin Configuration
| Pin 1 | VCC+ — Positive supply voltage (2.7 V to 10 V) |
| Pin 2 | IN+ — Non-inverting input (rail-to-rail common-mode) |
| Pin 3 | IN- — Inverting input (rail-to-rail common-mode) |
| Pin 4 | VCC- — Ground / negative supply |
| Pin 5 | OUTPUT — Open-drain comparator output (external pull-up required) |
Typical Applications
TS7221BILT is suitable for 6 applications: Battery Voltage Monitoring, Threshold / Window Detector, IoT / Wearable Sensor Nodes, Level Shifting and Logic Translation, Remote Keyless Entry (RKE) / Keyfob, Portable Medical / Hearing Aid Devices.
Battery Voltage Monitoring
The TS7221BILT's micropower quiescent current (single-digit uA) and rail-to-rail input make it ideal for battery voltage monitoring across 2.7V to 10V stacks. Its open-drain output drives an LED or microcontroller interrupt line directly with a single pull-up, and the B-grade input offset preserves accuracy within ~few mV at the threshold. Placed at the battery terminal, it enables low-power always-on monitoring that drains negligible current compared to the battery self-discharge.
Recommended
Threshold / Window Detector
In window detector circuits two TS7221BILT comparators compare an input signal against upper and lower reference voltages to flag out-of-range conditions. The open-drain outputs wire-OR together into a single alarm line, eliminating a discrete AND gate. Rail-to-rail input lets the references span the full supply range, and micropower draw suits always-on industrial sensor interfaces where a few mA of quiescent would defeat the design.
Recommended
IoT / Wearable Sensor Nodes
Wearable health monitors and IoT sensor nodes rely on the TS7221BILT's <10 uA quiescent current to extend coin-cell battery life into the multi-year range. The rail-to-rail input handles low-amplitude sensor signals near ground, while the SOT-23-5 footprint occupies less than 10 mm^2 of PCB area - critical for wristbands and patches. ESD protection to 2000V HBM (per datasheet absolute maximums) improves survival against handling and body-static discharge.
Recommended
Level Shifting and Logic Translation
The open-drain output with a pull-up to a separate logic rail allows the TS7221BILT to translate a sensor signal from a 3.3V analog domain to a 1.8V GPIO on a downstream processor, without needing a dedicated level shifter IC. This is a common trick in mixed-voltage systems where a comparator's output must interface with a lower-voltage host MCU. Micropower draw means the translation stage itself adds negligible overhead.
Recommended
Remote Keyless Entry (RKE) / Keyfob
The TS7221BILT's combination of SOT-23-5 small footprint, micropower draw, and 10V supply tolerance suits single-chip keyfob transmitter modules where every mm^2 and every uA count. The comparator can wake the MCU only when a button is pressed, holding the rest of the system in deep sleep. Industrial -40C to +85C operating range covers automotive temperature extremes, and rail-to-rail inputs allow direct connection to low-battery detection dividers.
Recommended
Portable Medical / Hearing Aid Devices
Hearing aids and portable medical monitors use the TS7221BILT for battery-end-of-life detection and signal-level thresholding. The micropower comparator sips current from a zinc-air or Li-ion button cell, and its small SOT-23-5 package fits inside miniature enclosures. Rail-to-rail inputs allow the entire battery voltage range to be monitored without missing the low-battery cutoff near ground.
Recommended
Recommended Products Summary
Engineering reference data for TS7221BILT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TS7221AILT | TS7221BIL | LMV331M7 | TS7221BILT-TR | LPV7215M5 |
|---|---|---|---|---|---|---|
| Package | SOT-23-5 | SOT-23-5 (same) | SOT-23-5 (same) | SOT-23-5 (same) | SOT-23-5 (same) | SOT-23-5 (same) |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | Texas Instruments | STMicroelectronics | Texas Instruments |
| Channels | 1 (single) | 1 | 1 | 1 | 1 | 1 |
| Output Type | Open-Drain | Open-Drain | Open-Drain | Open-Drain | Open-Drain | Push-Pull |
| Supply Voltage Max | 10 V | 10 V | 10 V | 5 V | 10 V | 5 V |
| Input Common-Mode | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Wider supply voltage range than cross-brand equivalents (vs LMV331M7)
- Tighter input offset voltage in B grade (vs TS7221AILT)
- Open-drain allows wired-OR and level-shifting (vs LPV7215M5)
Design Notes
Estimated: at 5V supply, the TS7221BILT draws single-digit microamperes of quiescent current (typically ~5-10 uA per the ST comparator family characteristics). The open-drain output pull-up resistor value sets a static current when the output is LOW: at 5V with 10 kohm pull-up, ~500 uA flows; raising to 100 kohm reduces this to ~50 uA but slows the rising edge. For battery-powered designs, use the largest pull-up that meets propagation-delay requirements - often 47 kohm to 100 kohm.
Place a 100 nF decoupling capacitor as close as possible to the VCC+ pin (pin 1) of the TS7221BILT to suppress supply noise that could couple into the comparator input stage. For open-drain outputs driving long traces, add a 100 kohm or smaller pull-up at the comparator end rather than at the load end to minimize the antenna effect of the trace. The SOT-23-5 thermal pad (none on this package) is not present, so thermal management is unnecessary up to the 10V supply range.
Critical: do not exceed the absolute maximum input voltage range of (VCC- - 0.3 V) to (VCC+ + 0.3 V) per the ST datasheet. Driving inputs beyond VCC+ can forward-bias ESD protection diodes and inject current into the supply rail, causing latch-up. For inputs that may exceed VCC, add a series resistor (10 kohm typical) to limit input current. Also note: the open-drain output requires an external pull-up - leaving the output floating will result in undefined logic level at HIGH state.
Compliance Information
RoHS and lead-free confirmed by ST product status; AEC-Q100 not applicable for this commercial-grade part. REACH compliance status inferred from ST general statement.
