BAP51-02,315 - PIN Diode 60V 50mA SOD-523 | NXP Semiconductors
MPN: BAP51-02,315 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.38 | $0.38 |
| 10 | $0.31 | $3.10 |
| 100 | $0.24 | $24.00 |
| 500 | $0.19 | $95.00 |
| 1,000 | $0.15 | $150.00 |
BAP51-02,315 Overview
A PIN diode is a semiconductor device with a wide, lightly doped intrinsic region sandwiched between P-type and N-type regions. At RF and microwave frequencies it behaves as an almost-ideal current-controlled resistance, which makes the PIN diode family the standard choice inside voltage-controlled attenuators, RF switches, phase shifters, and limiter circuits. Within the power-management hierarchy it sits under diodes -> RF diodes -> PIN diodes -> discrete semiconductor products.
Key features of the BAP51-02 include a very low diode capacitance of 0.55 pF, a maximum forward voltage of 950 mV, and a 60 V breakdown rating. The low capacitance minimizes insertion loss and isolation degradation in RF signal paths up to and beyond the GHz range, while the compact 1.2 x 0.8 mm SOD-523 footprint conserves board area in dense RF modules.
The intrinsic-region design gives the diode a well-controlled series resistance under forward bias, allowing accurate RF attenuation control when driven by a bias network. NXP documents the device in its BAP51-02 silicon PIN diode datasheet available as a PDF from nxp.com. Moisture sensitivity is MSL 1 with a 260 C peak reflow classification, simplifying lead-free reflow assembly.
Typical applications include RF switch and SPDT antenna switch paths, PIN-diode attenuators in transceiver front ends, VHF/UHF bias-switching networks, and general-purpose high-frequency switching in industrial and communications equipment.
A key design consideration: PIN diodes require DC bias current to set their RF resistance, so plan the bias network and RF choke values carefully, and derate the 715 mW dissipation above 25 C ambient.
This page adds information gain beyond the datasheet by consolidating distributor pricing, drop-in cross-references, packaging details, and practical RF design notes in one place.
Drop-in alternatives for BAP51-02,315 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
BAP51-02,125
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
BAP51-02-TP
β Drop-Inπ Reference alternative (not in catalog)
BAP51-02,315 Maximum Ratings & Electrical Characteristics
| Device Type | Silicon PIN diode (single) |
| Reverse Voltage (VR) | 60 V |
| Forward Current (IF) | 50 mA |
| Total Power Dissipation (Ptot) | 715 mW |
| Diode Capacitance (Cd) | 0.55 pF |
| Forward Voltage (VF max) | 950 mV |
| Configuration | Single diode |
| Package | SOD-523 (SC-79) SMD plastic |
| Mounting Type | Surface Mount |
| Moisture Sensitivity Level | MSL 1 |
| Peak Reflow Temperature | 260 C |
| Packing | Reel 7" Q1/T1 |
| Standard Package Quantity | 3000 |
| Minimum Order Quantity | 3000 |
| Lead Time (manufacturer) | 99 weeks |
BAP51-02,315 Pin Configuration
| Pin 1 | Cathode (K) β Cathode terminal (marked end per SOD-523 convention) |
| Pin 2 | Anode (A) β Anode terminal |
Typical Applications
BAP51-02,315 is suitable for 6 applications: RF Switch Circuits, Voltage-Controlled RF Attenuators, VHF/UHF Bias Switching Networks, RF Limiter Circuits, Phase Shifters and Control Circuits, General-Purpose High-Frequency Switching.
RF Switch Circuits
The BAP51-02,315 fits RF switch circuits because its 0.55 pF diode capacitance keeps off-state feedthrough low, while the forward-biased PIN structure presents a linear, current-controlled resistance for low insertion loss. In an SPDT switch, two BAP51-02 diodes are biased through RF chokes, with DC-blocking capacitors isolating the RF ports; switching the bias current routes the signal between arms. The 60 V rating provides headroom for moderate RF swing on antenna or PA paths. Performance trade-off: on-state loss is set by bias current, so higher bias current lowers RF resistance but raises DC consumption, making the device best suited to low-to-medium power switching through the GHz range.
Recommended
Voltage-Controlled RF Attenuators
PIN diode attenuators exploit the fact that a PIN diode's RF series resistance varies smoothly with forward bias current. The BAP51-02's well-controlled intrinsic region makes it suitable for Pi- and T-type attenuator networks in transceiver front ends and AGC loops. With 0.55 pF capacitance, the off state does not materially load the signal path, preserving dynamic range at the attenuation extremes. The 715 mW dissipation rating allows small continuous attenuation levels at modest signal powers; higher-power attenuators should use larger-package PIN diodes. Bias networks should use resistors or current sinks referenced to a control DAC for accurate, repeatable attenuation versus control-voltage characteristics across temperature.
Recommended
VHF/UHF Bias Switching Networks
In VHF and UHF front ends, the BAP51-02,315 is commonly used to switch filter banks, LNA paths, or antenna inputs under DC control. Its low capacitance minimizes detuning of high-Q resonant circuits when the diode is reverse-biased, and its fast PIN response supports rapid band hopping. Biasing is applied through inductors chosen to present high impedance at the operating frequency, typically a few hundred nH at 100-500 MHz. The SOD-523 footprint of roughly 1.2 x 0.8 mm allows placement directly at the switch node, shortening the RF path and lowering parasitic inductance. Designers should verify reverse voltage swing stays below the 60 V rating at the antenna node.
Recommended
RF Limiter Circuits
PIN diodes protect sensitive receivers by clamping high-power transients: the BAP51-02 can serve as the low-leakage limiter element in receiver front-end protectors. Under high RF drive, charge stored in the intrinsic region lets the diode conduct in both half-cycles, presenting a low resistance that shunts or reflects the excess power. Its 0.55 pF off-state capacitance keeps normal receiver sensitivity unaffected, and the 715 mW rating bounds the continuous leakage power it can absorb. For high-power radar or cellular band protection, pair the BAP51-02 with a larger PIN diode stage. Recovery time after the pulse should be verified against receiver AGC settling requirements in the system design.
Recommended
Phase Shifters and Control Circuits
Switched-line and loaded-line phase shifters use PIN diodes as low-loss RF switches selecting between path lengths. The BAP51-02,315's low 0.55 pF capacitance and controllable series resistance minimize amplitude ripple across phase states, which matters in phased-array and beamforming chains. Each diode is biased by a small driver current through high-impedance stubs or chokes; complementary diodes in a SPDT cell switch between the direct and delay line. At frequencies through the low-GHz range, insertion loss per diode remains a fraction of a dB at moderate bias. The compact SOD-523 package supports dense tiling in multi-bit phase shifter layouts on standard FR-4 or low-loss laminate.
Recommended
General-Purpose High-Frequency Switching
Beyond RF front ends, the BAP51-02,315 serves general-purpose high-frequency switching in test equipment, instrumentation, and industrial signal routing, where its 60 V rating exceeds most low-voltage logic environments and its low capacitance preserves signal fidelity above 100 MHz. Typical uses include muxing oscilloscope inputs, switching calibration relays' shunt paths, and gating clock or IF signals. Because the PIN diode requires DC bias current to conduct, the control circuitry must supply and sink this current; series resistors set the bias level and limit dissipation within the 715 mW budget. MSL 1 moisture rating and 260 C reflow compatibility simplify board assembly in volume production.
Recommended
Recommended Products Summary
Engineering reference data for BAP51-02,315 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BAP51-02,125 | BAP51-02-TP |
|---|---|---|---|
| Package | SOD-523 | SOD-523 - same | SOD-523 - same |
| Brand | NXP Semiconductors | NXP Semiconductors | Diodes Incorporated (MCC) |
| Reverse Voltage | 60 V | 60 V | 60 V |
| Forward Current | 50 mA | 50 mA | 50 mA |
| Power Dissipation | 715 mW | 715 mW | 715 mW |
| Diode Capacitance | 0.55 pF | 0.55 pF | 0.55 pF (typ) |
| Packing | Reel 7" Q1/T1, 3000 pcs | Reel, qty per NXP packing standard | Tape & Reel / cut tape available |
Key Differentiators
- Very low diode capacitance in the smallest common footprint (vs BAP51-02-TP)
- Manufacturer-direct sourcing continuity (vs BAP51-02-TP)
- Moderate 60 V rating for compact RF switching (vs BAP51-02,125)
Design Notes
The 715 mW Ptot rating of the BAP51-02 applies at the reference ambient temperature (typically 25 C) and must be derated linearly toward zero at the maximum junction temperature. Estimated: at 10 mA forward bias and ~1 V forward drop, dissipation is only about 10 mW, leaving large margin; risk arises only in limiter duty or high-current bias where continuous dissipation approaches hundreds of milliwatts. Follow the datasheet derating curve and verify worst-case junction temperature in your enclosure.
Keep the RF path to the BAP51-02,315 as short as possible; SOD-523 pad geometry should follow the manufacturer's recommended land pattern, with the cathode band clearly identified in the silkscreen to avoid reverse mounting, a common rework cause. Place bias chokes and DC-blocking capacitors adjacent to the diode so the RF node sees minimal added inductance. A solid ground plane under the diode area reduces parasitic radiation in switch and attenuator layouts.
PIN diodes need DC bias current to reach their low-RF-resistance state; a design that relies on signal-level self-bias will show excessive insertion loss and distortion. Ensure the control network can supply the required bias current and that reverse-voltage swing on the diode never exceeds the 60 V rating - antenna nodes can ring well above nominal RF amplitude. Also note NXP lists a 99-week factory lead time, so secure distributor stock early in the project schedule.
Compliance Information
NXP supplies the part with 260 C peak reflow classification consistent with lead-free assembly; explicit RoHS/REACH declarations should be confirmed on the NXP product page or distributor listing.
