BAP70-02 - Silicon PIN Diode 50V 100mA SOD-523 | NXP Semiconductors
MPN: BAP70-02 β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.12 | $0.12 |
| 10 | $0.09 | $0.90 |
| 100 | $0.06 | $6.00 |
| 500 | $0.045 | $22.50 |
| 1,000 | $0.032 | $32.00 |
BAP70-02 Overview
A PIN diode is a special type of diode with a wide, lightly doped intrinsic semiconductor layer sandwiched between P-type and N-type regions. At RF frequencies, the forward-biased intrinsic layer behaves as a current-controlled resistor, making PIN diodes the preferred choice for RF switches, step attenuators, and variable-gain circuits where ordinary PN junction diodes would introduce unacceptable harmonic distortion. Within the signal-chain hierarchy, the BAP70-02 belongs to the RF PIN diode family, a subcategory of discrete RF diodes used in front-end modules, gain-control networks, and antenna-line switching.
Key features include high breakdown voltage providing robust headroom for antenna-line switching, low diode capacitance minimizing insertion loss and off-state feedthrough, and very low series inductance enabled by the compact SOD-523 footprint. The AEC-Q101 qualification supports automotive RF systems such as car radio and satellite radio tuners.
Technically, the BAP70-02 is a planar PIN diode whose controlled intrinsic-layer resistance varies smoothly with forward bias current, allowing linear, low-distortion attenuation when DC bias current is adjusted. Ordinary PN diodes cannot match this property because their charge storage and junction behavior create distortion in RF switching duty.
Typical applications include RF attenuators in satellite (SAT) TV LNB and tuner modules, car radio front ends, and UHF/VHF switching circuits up to 1 GHz, per the NXP product page.
Design consideration: bias the diode with a well-defined DC return path (RF choke or resistor network); PIN diode RF resistance is set by forward current, not voltage, so bias network design directly determines attenuation accuracy.
This page synthesizes distributor pricing, drop-in alternative guidance, and practical bias-layout design notes not found in the manufacturer datasheet.
Drop-in alternatives for BAP70-02 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:
BAP70-02/A2,115
β Drop-Inπ Reference alternative (not in catalog)
BAP70-02,115
β Drop-Inπ Reference alternative (not in catalog)
BAP70-02 Maximum Ratings & Electrical Characteristics
| Device Type | Silicon planar PIN diode |
| Application | RF attenuator / RF switching up to 1 GHz |
| Reverse Voltage (VR) | 50 V |
| Continuous Forward Current (IF) | 100 mA |
| Total Power Dissipation (Ptot) | 415 mW |
| Series Inductance | Very low (per NXP datasheet) |
| Package | SOD-523 (SC-79) ultra-small SMD plastic |
| Mounting Type | Surface Mount |
| Pin Count | 2 |
| Automotive Qualification | AEC-Q101 qualified |
| Technology | Planar PIN |
| Ordering Code (Tape & Reel) | BAP70-02,115 |
| RoHS Status | Compliant |
BAP70-02 Pin Configuration
| Pin 1 | Cathode (K) β Cathode terminal; band-marked end of SOD-523 package |
| Pin 2 | Anode (A) β Anode terminal; forward bias from pin 2 to pin 1 sets the RF resistance |
Typical Applications
BAP70-02 is suitable for 6 applications: Satellite TV (SAT) LNB Attenuators, Car Radio RF Front Ends, UHF/VHF RF Switching up to 1 GHz, Variable-Gain Amplifier (VGA) Bias Networks, Antenna-Line Protection and Switching, RF Test and Measurement Attenuator Pads.
Satellite TV (SAT) LNB Attenuators
In satellite TV LNB and tuner modules, the BAP70-02 serves as a current-controlled RF resistor in AGC and step-attenuator networks. Its low diode capacitance minimizes insertion loss and off-state feedthrough in the 950-2150 MHz IF path, while the 50 V reverse voltage provides robust headroom against antenna-line transients. The planar PIN structure gives smooth resistance-versus-current behavior, so bias-current control yields low-distortion, linear attenuation - critical for preserving signal quality in the satellite downlink chain. The SOD-523 ultra-small footprint fits the dense tuner layouts typical of LNB modules.
Recommended
Car Radio RF Front Ends
Automotive car radio front ends use the BAP70-02 in gain-control and antenna-switching circuits where AEC-Q101 qualification is mandatory. The 50 V rating withstands the large signals and static events present on vehicle antenna lines, and low diode capacitance keeps the AM/FM front-end Q and sensitivity high. Because PIN diode RF resistance is controlled by DC bias current, designers can implement smooth AGC across the full broadcast band with a simple current source. The compact SOD-523 package suits the high-density head-unit tuner PCBs used in modern vehicles.
Recommended
UHF/VHF RF Switching up to 1 GHz
The BAP70-02 functions as a series or shunt RF switch element in UHF/VHF paths up to 1 GHz, per the NXP application description. At high forward bias the intrinsic layer resistance drops to a low value for low insertion loss; at zero or reverse bias the low capacitance limits off-state coupling. The 50 V reverse rating provides headroom for switching large RF swing. Its very low series inductance, enabled by the SOD-523 outline, keeps resonances above the operating band, maintaining consistent isolation across the switched frequency range.
Recommended
Variable-Gain Amplifier (VGA) Bias Networks
In VGA and gain-trim circuits, the BAP70-02 acts as the voltage-variable resistor element in a resistive Pi- or T-attenuator driven by a DC control current. The smooth, monotonic series-resistance curve of the planar PIN structure gives predictable gain steps without the harmonic distortion an ordinary PN diode would inject. Because control is current-based, the control DAC or current mirror directly sets attenuation with good repeatability. Using matched pairs of BAP70-02 in symmetrical networks improves attenuation tracking across temperature and unit-to-unit variation.
Recommended
Antenna-Line Protection and Switching
The 50 V reverse breakdown of the BAP70-02 makes it suitable for antenna-line switching and protection roles where static and large broadcast signals appear. Mounted in SOD-523 on the antenna input of a tuner or receiver module, it can clamp or steer RF energy under bias control while presenting minimal capacitance when off. The AEC-Q101 qualification supports use in vehicle-external antenna paths subject to harsh environments. Designers should provide a defined DC return path so the diode operating point is stable across temperature and frequency.
Recommended
RF Test and Measurement Attenuator Pads
In RF test equipment and laboratory fixtures, the BAP70-02 builds electronically controlled attenuator pads that level signal-generator output or protect sensitive analyzer inputs. The current-controlled resistance of the planar PIN die provides repeatable, low-distortion attenuation up to 1 GHz, and the low capacitance preserves wideband flatness. The 415 mW power dissipation rating bounds the maximum RF power the pad can absorb; for high-power fixtures, distribute attenuation across multiple series BAP70-02 devices with individual bias networks to share thermal and voltage stress.
Recommended
Recommended Products Summary
Engineering reference data for BAP70-02 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BAP70-02,115 | BAP70-02/A2,115 |
|---|---|---|---|
| Package | SOD-523 (SC-79) | SOD-523 (SC-79) - same | SOD-523 (SC-79) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Reverse Voltage (VR) | 50 V | 50 V | 50 V |
| Forward Current (IF) | 100 mA | 100 mA | 100 mA |
| Power Dissipation (Ptot) | 415 mW | 415 mW | 415 mW |
| AEC-Q101 Qualification | Qualified | Qualified | Qualified |
| Frequency Range | Up to 1 GHz | Up to 1 GHz | Up to 1 GHz |
| Lifecycle Status | EOL (per NXP product page) | EOL - residual distributor stock | EOL - residual distributor stock |
Key Differentiators
- AEC-Q101 automotive qualification (vs Generic SOD-523 RF PIN diodes)
- Low distortion current-controlled resistance (vs BAT46 / 1N5711 Schottky families)
- Ultra-small low-inductance package (vs Larger SOD-323 / SOD-123 PIN diodes)
Design Notes
Bias network design determines attenuation accuracy: the PIN diode RF resistance of the BAP70-02 is set by DC forward current, not forward voltage. Provide a defined DC return path (RF choke or resistor network) and block DC from the RF line with coupling capacitors. Add isolation resistors in the bias feed so the control network does not load the RF path. Keep the SOD-523 pads connected to controlled-impedance microstrip; avoid stubs longer than a few mm above 500 MHz to prevent passband ripple.
Polarity errors are the most common failure mode with SOD-523 PIN diodes. Pin 1 is the cathode (band-marked); verify both the part marking and the PCB silkscreen before assembly. Also do not substitute a Schottky diode (e.g., BAT46 or 1N5711 family) for the BAP70-02: Schottky devices are voltage-controlled and will introduce distortion and incorrect resistance-versus-current behavior in attenuator circuits. Finally, this part is EOL at NXP - secure last-time-buy stock or qualify the replacement before design freeze.
Estimated: with the rated 415 mW total power dissipation in the small SOD-523 package, junction temperature rise depends on the board thermal resistance (Rth j-s is specified in the NXP datasheet relative to the solder point). For attenuator duty near the dissipation limit, provide solid copper pour connected to both pads and share RF power across multiple series diodes with individual bias networks. Above roughly 300 mW per device, verify junction temperature stays within the datasheet maximum at your maximum ambient.
The low diode capacitance and very low series inductance of the BAP70-02 keep insertion loss low and isolation high up to 1 GHz, but off-state feedthrough rises with frequency as the capacitive reactance falls. In shunt-switch topologies above 500 MHz, consider two series-shunt diode sections to restore isolation. Use NXP's published S-parameter model (S-parameters BAP70-02 ZIP, Rev 1.0, Jun 2012, available on the NXP product page) for simulation instead of assuming ideal behavior.
Compliance Information
AEC-Q101 qualified (automotive discrete standard) per NXP/datasheets.com data. AEC-Q100 is not applicable since this is a discrete diode, not an IC. RoHS compliance follows from the NXP ,115 lead-free ordering code.
