LM2903PT - Dual Low-Power Voltage Comparator, +2V to +36V | STMicroelectronics
N.º da peça: LM2903PT ✓ AtivoLM2903PT Visão geral
A voltage comparator is an amplifier IC that compares two input voltages and switches its output when the difference between them changes sign. In system terms a comparator sits at the base of the hierarchy of analog signal conditioning: comparator -> amplifier IC -> analog integrated circuit -> semiconductor, and it is the natural front end for threshold detection, sensor signalling and window monitoring. Because the LM2903 output is an open-collector style transistor stage, it interfaces directly with TTL, MOS and CMOS logic families and can pull a rail low without an external push-pull driver.
Key features of the LM2903PT include a common-mode input voltage range that includes ground even when operated from a single supply, very low supply current drain of 0.4 mA, low input bias current of 25 nA typical, and low input offset current of +/-5 nA typical. The low offset current means the two comparators of the pair track each other closely, which matters when one channel is used as a reference and the other as the active comparator in a window-detector arrangement.
The device is built on a bipolar monolithic process, which explains the wide supply range and the ability to accept input signals near and beyond ground. Two comparators share one package, so a single 8-pin TSSOP footprint can implement a full two-threshold window comparator, a dual-level battery monitor, or a pair of independent limit detectors for analog signals with only one board space increment.
Typical applications include industrial control and instrumentation thresholds, battery-powered monitoring and protection circuits, motor and solenoid drive control loops, sensor interface modules, and consumer equipment power supervision. Because supply current is independent of the supply voltage, the part remains usable across wide battery-discharge ranges without the quiescent current rising as the cell voltage falls.
When laying out the design, route the two input nets as short and separated as possible, keep the open-collector output pull-up resistor close to the device, and confirm that the logic family connected to the output can tolerate the pull-up voltage. Use the pin-description table in the STMicroelectronics datasheet when assigning PCB tracks.
This page brings together the supply-voltage and input-current characteristics, drop-in alternatives that share the identical TSSOP-8 footprint, comparison tables and practical design notes that go beyond a bare parameter listing, helping engineers qualify the part quickly for industrial, automotive-adjacent and consumer designs.
Alternativas drop-in para LM2903PT — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com LM2903PT (mesmo formato e footprint) — diferindo em Package, Number of Channels, Comparator Type, Mounting Type, Output Type.
LM2903PW
✅ Drop-In ⚠️ Especificações não verificadasConsulte o preço
Ver ficha técnica →LM393PT
✅ Drop-In ⚠️ Especificações não verificadasConsulte o preço
Ver ficha técnica →LM393PW
✅ Drop-In ⚠️ Especificações não verificadasConsulte o preço
Ver ficha técnica →LM2904PT
✅ Drop-In ⚠️ Especificações não verificadasConsulte o preço
Ver ficha técnica →LM393WPT
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LM2904PW
✅ Drop-InConsulte o preço
Ver ficha técnica →LM2904P3
✅ Drop-InConsulte o preço
Ver ficha técnica →LM2903PT Classificações máximas e características elétricas
| Device Type | Dual low-power voltage comparator |
| Number of Channels | 2 |
| Single Supply Voltage Range | +2 V to +36 V |
| Dual Supply Voltage Range | +/-1 V to +/-18 V |
| Corrente de alimentação | 0.4 mA (independent of supply voltage) |
| Power Consumption per Comparator | 1 mW at +5 V |
| Input Bias Current | 25 nA typical |
| Input Offset Current | +/-5 nA typical |
| Logic Compatibility | TTL, MOS and CMOS compatible interfaces |
| Encapsulamento | TSSOP-8 (8TSSOP), 8 pins |
| Tipo de montagem | Surface mount |
| Process Technology | Bipolar monolithic |
Configuração de pinos do LM2903PT
| Pino 1 | OUT1 — Comparator 1 output (open-collector style) |
| Pino 2 | IN1- — Comparator 1 inverting input |
| Pino 3 | IN1+ — Comparator 1 non-inverting input |
| Pino 4 | GND — Ground |
| Pino 5 | IN2+ — Comparator 2 non-inverting input |
| Pino 6 | IN2- — Comparator 2 inverting input |
| Pino 7 | OUT2 — Comparator 2 output (open-collector style) |
| Pino 8 | VCC — Positive supply voltage |
Aplicações típicas
LM2903PT é adequado para 6 aplicaçãos: Industrial Threshold Detection, Battery-Powered Protection and Monitoring, Motor Drive and Solenoid Control Loops, Sensor Interface and Conditioning, Power Supply Sequencing and Rail Supervision, LED Driver and Lighting Feedback.
Industrial Threshold Detection
The LM2903PT suits industrial control modules that must decide whether a 4-20 mA or 0-10 V process signal has crossed a setpoint. Its single-supply range of +2 V to +36 V lets the comparator sit directly on a 24 V loop supply without a separate low-voltage regulator, and the 0.4 mA supply current stays flat as the rail rises. Placing one channel on the signal and the other on a precision reference builds a two-threshold window detector in a single 8-pin TSSOP footprint, with the open-collector outputs driving a PLC input stage through a pull-up. The wide common-mode range, which includes ground even on a single supply, allows the lower rail of the loop to be sensed without level shifting.
Recomendado
Battery-Powered Protection and Monitoring
In battery-operated equipment the LM2903PT provides low-quiescent over-voltage, under-voltage and temperature protection without adding measurable battery drain. The STMicroelectronics datasheet specifies 0.4 mA supply current independent of supply voltage, so the protection circuit does not consume progressively more current as the cell discharges, and the +2 V lower limit keeps the device alive deep into the discharge curve. Two channels allow a fast over-voltage cut-off plus a slower under-voltage warning, both with open-collector outputs driving a load switch or a system reset. Because the common-mode input range includes ground, cell and divider outputs sitting near 0 V can be compared directly.
Recomendado
Motor Drive and Solenoid Control Loops
The LM2903PT is used as the current or speed comparator in small motor and solenoid control boards, where the decision to energise a driver depends on comparing a sense amplifier output against a reference. The bipolar process and wide supply capability let the comparator run from the same rail as the driver logic, from +5 V up to +36 V, which simplifies the power tree on a 24 V actuator board. The 0.4 mA supply current is negligible beside the driver stage, and the two channels can monitor two independent axes or provide a hysteresis pair on a single threshold. Open-collector outputs suit gate drivers with an active-high enable, and the small TSSOP-8 footprint keeps the layout away from high-current switching loops.
Recomendado
Sensor Interface and Conditioning
In sensor front-end modules the LM2903PT converts a slow analogue sensor output into a clean logic event, for example in light, temperature or capacitive proximity modules. With 25 nA typical input bias current and +/-5 nA typical input offset current, the comparator adds minimal loading to a high-impedance sensor node and keeps channel-to-channel tracking tight, which matters when one channel is the reference. The low 0.4 mA supply current suits battery-powered sensor nodes where the whole module must run for months on a coin cell. The open-collector output can pull down a microcontroller wake-up line directly through a pull-up resistor, avoiding the need for an additional inverter stage.
Recomendado
Power Supply Sequencing and Rail Supervision
The LM2903PT fits power-supervision and sequencing circuits where a supervisor IC would be overkill. Two independent channels compare a divided rail voltage against a reference to assert a power-good or reset signal, and the wide +2 V to +36 V supply range means one part can monitor rails from 3.3 V to 36 V without level shifting. The flat 0.4 mA supply current keeps the monitoring overhead constant across a large operating range, an important point in line-operated equipment that also handles battery backup. The open-collector output releases a latch or enables a load switch through a pull-up, and the TSSOP-8 package keeps the supervision block to a single small footprint beside the power stage.
Recomendado
LED Driver and Lighting Feedback
In constant-current LED drivers the LM2903PT compares the sense resistor voltage against a reference to close the current-regulation loop. The wide supply range allows the comparator to sit on the same high-voltage rail as the switching stage, while the low 0.4 mA supply current contributes nothing measurable to the driver efficiency budget. Two channels permit a dual implementation, one regulating current and one monitoring LED temperature or supply undervoltage. The bipolar input stage handles the fast edges typical of switch-mode drivers, and the open-collector output drives the controller error input or a cycle-by-cycle disable through a pull-up resistor.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para LM2903PT — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | LM2903PW | LM393PT | LM393PW | LM2904PT | LM393WPT |
|---|---|---|---|---|---|---|
| Package | TSSOP-8 | TSSOP-8 - same | TSSOP-8 - same | TSSOP-8 - same | TSSOP-8 - same | TSSOP-8 - same |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | Texas Instruments |
| Comparator Channels | 2 | 2 | 2 | 2 | 2 | 2 |
| Single Supply Voltage Range | +2 V to +36 V | +2 V to +36 V | +2 V to +36 V | +2 V to +36 V | +2 V to +36 V | 2 V to 36 V |
| Dual Supply Voltage Range | +/-1 V to +/-18 V | +/-1 V to +/-18 V | +/-1 V to +/-18 V | +/-1 V to +/-18 V | +/-1 V to +/-18 V | +/-1 V to +/-18 V |
| Logic Interface Compatibility | TTL, MOS and CMOS | TTL, MOS and CMOS | TTL, MOS and CMOS | TTL, MOS and CMOS | TTL, MOS and CMOS | TTL, MOS and CMOS |
Principais diferenciais
- Supply current stays flat at 0.4 mA across the entire +2 V to +36 V supply range (vs LM2904PW)
- Very low input bias and offset currents preserve high-impedance sensor nodes (vs LM393PT)
- Two independent channels in one 8-pin TSSOP footprint (vs LM2903P)
- Legacy-compatible open-collector interface avoids level translators (vs TLV2402ID)
Notas de projeto
Place the pull-up resistor for each open-collector output directly between the output pin and the logic supply, as close to the device as practical, and keep the output trace short. The pull-up carries the switching current, so a long trace between the resistor and the pin acts as an antenna and couples output edges into adjacent analogue inputs. A 10 kOhm to 100 kOhm pull-up is a reasonable starting range when the receiving logic input capacitance allows it; lower values speed up the falling edge but raise the continuous sink current, so check it against the output sink current limit in the datasheet.
Keep the two inverting and non-inverting input nets short and separated from each other and from the supply pins. Input bias current of 25 nA typical means that even a high-impedance source can be pulled by leakage on a long, dirty track, so route the inputs over a continuous ground plane and avoid running them parallel to switching nets. Supply decoupling should be a local 100 nF ceramic plus a bulk capacitor near the comparator, because the 0.4 mA supply current is constant only if the supply node itself is low impedance across the full +2 V to +36 V range.
Do not assume the output actively sources current. This comparator uses an open-collector style output stage, so leaving the output without a pull-up leaves the node floating and the logic state undefined, which is a common cause of intermittent behaviour in prototypes. Also note that the common-mode input range includes ground but does not extend to the positive rail, so do not drive the inputs above the supply rail; clamp or attenuate any signal that can exceed it, and check the differential input limit in the datasheet before applying large transient signals.
Estimated: with a single 5 V supply and a 2 mA total load through both channels, average dissipation is roughly (5 V - 0.2 V) x 2 mA = 9.6 mW, which is negligible for the TSSOP-8 thermal design. The dominant power term in most designs is the pull-up resistor dissipation, not the comparator: a 10 kOhm pull-up to 5 V with the output held low dissipates about 2.5 mW continuously. Estimate this for every channel before sizing the regulator that feeds the logic rail.
For window-detection configurations where both channels switch near the same threshold, stagger the two reference values slightly so the outputs do not cross over simultaneously, which reduces simultaneous output transitions and the associated supply disturbance on a shared rail. Where a switching node is unavoidable, keep the comparator ground reference close to the device ground and provide a dedicated local return path rather than relying on a long shared ground trace through the board.
Informações de conformidade
No RoHS, REACH or AEC-Q100 statements appear in the manufacturer or distributor material for this ordering code; confirm the current declarations with STMicroelectronics before release. The device is described in the datasheet as a low-power dual voltage comparator intended for direct TTL, MOS and CMOS interfacing.
