RP173N331B-TR-FE - 3.3V 150mA LDO Regulator SOT-23-5 | Nisshinbo
N.º da peça: RP173N331B-TR-FE ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $0.71 | $0,71 |
| 10 | $0.59 | $5,90 |
| 100 | $0.46 | $46,00 |
| 500 | $0.38 | $190,00 |
| 1.000 | $0.32 | $320,00 |
| 3.000 | $0.27 | $810,00 |
RP173N331B-TR-FE Visão geral
An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable output voltage even when the input voltage is only slightly above the desired output. Within the power management hierarchy, the RP173N331B sits under linear regulators, which sit under voltage regulators, which are part of the broader power management IC category. Unlike switching regulators, an LDO trades efficiency for ultra-low noise and a minimal external bill of materials, requiring only input and output capacitors.
Key features of the RP173N331B-TR-FE include reverse-current protection, a built-in current limiter, thermal shutdown, and CMOS process technology that delivers the 2.0 µA quiescent current. The fixed 3.3 V output is internally trimmed, so no external feedback resistors are required. The combination of small SOT-23-5 footprint, low IQ, and reverse-current blocking makes the part especially attractive in standby-power designs where the regulator must not leak back into a battery when system voltage collapses.
The RP173N331B uses a PMOS pass element architecture, which is why the input voltage can swing close to the output while still regulating, and why the reverse-current block is straightforward to implement. Internal protection features (foldback current limit and thermal shutdown with auto-recovery) allow the part to survive momentary short-circuit and overtemperature events without latch-up. The reference and error amplifier are trimmed at wafer level, so output accuracy is achieved without laser trim or external pots.
Typical applications for the RP173N331B include standby rails in white goods and home appliances, IoT sensor nodes powered by coin-cell or Li-ion batteries, microcontroller (MCU) always-on domains, RTC and memory backup supplies, and post-regulation after a switching converter in noise-sensitive analog blocks. The 3.3 V fixed output is a direct match for many low-power MCUs and Bluetooth Low Energy (BLE) SoCs.
When designing with the RP173N331B, place the input and output capacitors as close to the IC as possible. A 1 µF or larger ceramic on each rail is normally sufficient; verify stability with the manufacturer's ESR-versus-capacitance chart before substituting. Ensure that VIN never exceeds 11 V, even under transient conditions, and that PCB layout keeps the thermal pad area adequate for the expected dissipation (max ~150 mW in SOT-23-5 at 25 °C).
This page synthesizes distributor pricing, same-brand and cross-brand drop-in alternatives, application reference designs, and practical design notes not collected in any single location on the manufacturer datasheet or distributor product page.
Alternativas drop-in para RP173N331B-TR-FE — 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 RP173N331B-TR-FE (mesmo formato e footprint) — diferindo em Package, Manufacturer, Output Voltage.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
RP173N331B-TR-FE
✅ Drop-In✓ Em estoque
$0.27 / unidade
Ver ficha técnica →RP170N331B-TR-FE
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
RP173N321B-TR-FE
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
RP173N401B-TR-FE
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
RP154N037B-TR-FE
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
XC6206P332MR
✅ Drop-In✓ Em estoque
$0.041 / unidade
Ver ficha técnica →RP173N331B-TR-FE Classificações máximas e características elétricas
| Manufacturer | Nisshinbo Micro Devices Inc. |
| Part Series | RP173x |
| Regulator Topology | Low-Dropout (LDO), Linear, Fixed |
| Output Polarity | Positive |
| Tensão de saída | 3.3 V (fixed) |
| Corrente de saída (máx.) | 150 mA |
| Input Voltage (max, datasheet) | 11 V |
| Input Voltage (max, distributor listing) | 9.8 V |
| Dropout Voltage (typ) | 610 mV at 150 mA |
| Quiescent Current (typ) | 2.0 µA |
| Protection Features | Reverse-Current Protection, Current Limit, Thermal Shutdown |
| Encapsulamento | SOT-23-5 |
| Tipo de montagem | Surface Mount |
| Status RoHS | Compliant |
| Livre de halogênio | Yes (per DigiChip listing) |
| Lifecycle Stage | Active |
| Process Technology | CMOS |
Configuração de pinos do RP173N331B-TR-FE
| Pino 1 | VIN — Input supply voltage; connect to unregulated source, decouple with >=1 µF ceramic |
| Pino 2 | GND — Common ground reference for input and output |
| Pino 3 | CE/NC — Chip Enable or No-Connect depending on suffix variant; see datasheet pin map for the specific ordering code |
| Pino 4 | NC — Not connected internally; leave floating or tie to GND |
| Pino 5 | VOUT — Regulated 3.3 V output; decouple with >=1 µF ceramic to GND |
Aplicações típicas
RP173N331B-TR-FE é adequado para 6 aplicaçãos: Battery-Backed RTC and Memory Standby Rail, IoT Sensor Node MCU Power, Home Appliance Standby Supply, Post-Regulator After Switching Converter, USB-Powered Device 3.3 V Rail, Industrial Sensor Transmitter.
Battery-Backed RTC and Memory Standby Rail
The RP173N331B-TR-FE is well suited for always-on 3.3 V rails that power RTC ICs and SRAM/FRAM backup domains in mains-powered but battery-backed products. Its 2.0 µA typical quiescent current extends coin-cell life during brownouts, and the built-in reverse-current protection prevents the backup battery from discharging back into a discharged system rail. The fixed 3.3 V output matches the VCC domain of most RTCs (e.g., Nisshinbo/NXP PCF8563, Maxim DS3231) and low-power SRAMs, eliminating the need for feedback resistors. Compared with a switching regulator, the LDO adds no switching noise - important when the same PCB also carries RF wake-up circuitry. Place a 1 µF X7R ceramic on input and output, and ensure VIN does not exceed 11 V even on hot-plug transients.
Recomendado
IoT Sensor Node MCU Power
In wireless sensor nodes powered by 2x AA or a single CR2032 / Li-ion cell, the RP173N331B-TR-FE provides a regulated 3.3 V rail for low-power MCUs and BLE SoCs from its wide input range. The 2.0 µA quiescent current dominates sleep-mode battery life; combined with a load switch, the node can idle on <5 µA total. The 150 mA peak load capability is sufficient for transmission bursts from sub-GHz radios and BLE 5.x modules. The SOT-23-5 footprint occupies only ~9 mm² of PCB area, leaving room for small sensor packages. Reverse-current protection is critical here, as it prevents the LDO from feeding back into the cell when VIN collapses during transmit peaks.
Recomendado
Home Appliance Standby Supply
White goods, set-top boxes, and smart-home hubs spend 99% of their life in standby yet must respond instantly to remote or button inputs. The RP173N331B-TR-FE delivers a clean 3.3 V for the always-on MCU and IR/BLE receiver from a 9 V or 12 V rectified auxiliary rail, drawing only 2.0 µA to minimize standby power consumption below the 0.5 W regulatory limits now in force across the EU and California. The 11 V absolute-max input is more than enough for 9 V and 12 V auxiliary windings, and internal thermal shutdown plus foldback current limit protect the regulator from short-circuit faults during assembly. The reverse-current block also helps when the appliance is unplugged and bulk caps discharge asymmetrically.
Recomendado
Post-Regulator After Switching Converter
In mixed-signal designs, a switching DC-DC converter handles the bulk step-down with high efficiency, but its ripple can couple into sensitive analog or RF stages. The RP173N331B-TR-FE placed as a second-stage LDO cleans the ripple down to its own noise floor while still sourcing up to 150 mA. With a 3.3 V fixed output, it can power ADC references, low-noise op-amps, or sensor analog domains from a 5 V intermediate rail. Compared to a higher-current LDO, the 150 mA rating matches typical analog block budgets without oversizing cost. The 11 V input rating gives design margin for transient spikes on the 5 V rail.
Recomendado
USB-Powered Device 3.3 V Rail
USB-powered peripherals (HID devices, programmers, low-speed data loggers) need a regulated 3.3 V from the 5 V VBUS rail. The RP173N331B-TR-FE accepts the 5 V input with comfortable headroom under its 11 V absolute-max rating and delivers 150 mA - more than enough for the MCU plus a couple of indicator LEDs or a small display. The CMOS architecture's 2.0 µA quiescent current keeps suspend-mode current low for USB-compliant devices. Reverse-current protection is helpful when the device is unplugged and downstream caps discharge into the upstream rail. The SOT-23-5 footprint integrates easily into space-constrained dongle enclosures.
Recomendado
Industrial Sensor Transmitter
In 4-20 mA loop-powered or 24 V industrial sensors, the RP173N331B-TR-FE provides a 3.3 V rail for the sensing element and front-end amplifier after a pre-regulator stage. Its industrial temperature rating and reverse-current protection make it suitable for harsh-environment installations where input polarity or load transients could otherwise damage a less-protected LDO. The 11 V absolute-max input allows operation from a 24 V bus pre-regulated down to 5-9 V. With 150 mA available, the regulator can power an MCU, an op-amp front end, and a small isolated communications interface simultaneously.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para RP173N331B-TR-FE — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | RP170N331B-TR-FE | RP173N321B-TR-FE | RP173N401B-TR-FE | RP154N037B-TR-FE | XC6206P332MR |
|---|---|---|---|---|---|---|
| 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 | Nisshinbo Micro Devices | Nisshinbo Micro Devices | Nisshinbo Micro Devices | Nisshinbo Micro Devices | Nisshinbo Micro Devices | Torex Semiconductor |
| Output Voltage | 3.3 V | 3.3 V | 3.2 V | 4.0 V | 3.7 V | 3.3 V |
| Output Current (max) | 150 mA | 150 mA | 150 mA | 150 mA | 150 mA (dual output) | 150 mA |
| Reverse-Current Protection | Yes | Yes | Yes | Yes | Yes | No (depends on sub-version) |
Principais diferenciais
- Built-in reverse-current protection (vs XC6206P332MR)
- Wider input voltage headroom (11 V) (vs XC6206P332MR)
- Ultra-low 2.0 µA quiescent current (vs RP170N331B-TR-FE)
Notas de projeto
Place input and output ceramic capacitors (>=1 µF X7R, 10 V rating) as close as possible to the VIN and VOUT pins to ensure regulator stability and minimize input-voltage ringing during load transients. The CMOS architecture typically tolerates ESR from ~10 mΩ to ~500 mΩ; verify against the manufacturer's ESR-versus-capacitance curve if using non-ceramic capacitors. If the source impedance is high (long PCB traces, batteries), add a 10 Ω series resistor with the input capacitor to damp LC ringing.
Estimated: at VIN = 5 V, VOUT = 3.3 V, IOUT = 150 mA, the regulator dissipates approximately (5 - 3.3) × 0.150 = 0.255 W. The SOT-23-5 has a θJA of about 250 °C/W on a standard JEDEC 1-oz 2-layer test board, giving a junction temperature rise of ~64 °C above ambient. At 25 °C ambient this yields ~89 °C junction, well below the 150 °C thermal shutdown. However, at VIN = 9 V the dissipation rises to ~0.86 W and the junction could approach shutdown in enclosed housings; provide copper pour on the GND pin and consider reducing VIN via a pre-regulator.
Do not exceed the 11 V absolute maximum input voltage - transients on the input rail (e.g., from inductive loads sharing the supply) can destroy the part. When substituting the 'FE' (Pb-free / halogen-free) suffix part on an existing layout that used the non-FE version, double-check the land pattern matches the SOT-23-5 standard; some Nisshinbo datasheets note a slightly different exposed pad handling between suffixes. For reverse-current protection to function, VOUT must remain higher than VIN long enough for the internal comparator to switch - typically <1 µs response, which is adequate for most battery-backup scenarios.
Informações de conformidade
RoHS compliant and halogen-free per DigiChip datasheet listing and DigiKey product page. Not AEC-Q100 qualified - choose RP111H331B-T1-JE for automotive applications.
