BAP70-04W,115 - Dual Series PIN Diode 50V SC-70 | NXP
MPN: BAP70-04W,115 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.18 | $0.18 |
| 10 | $0.14 | $1.40 |
| 100 | $0.09 | $9.00 |
| 500 | $0.065 | $32.50 |
| 1,000 | $0.048 | $48.00 |
BAP70-04W,115 Overview
A PIN diode is a semiconductor diode with an intrinsic (undoped) layer sandwiched between P-type and N-type regions. Under forward bias it behaves as a nearly linear RF resistor whose resistance is controlled by DC forward current; under reverse bias it presents a very small capacitance to the RF path. This current-controlled resistance property makes PIN diodes the standard choice for RF switching, attenuation and gain control in the signal chain between antenna and transceiver, where conventional Schottky or junction diodes would add unwanted distortion.
Key features of the BAP70-04W include low diode capacitance (0.3 pF at 20V reverse bias), low series resistance in the conductive state for insertion-loss control, high breakdown voltage of 50 V, and 260 mW total power dissipation in the SOT-323 package. The series pair halves the effective capacitance relative to a single diode, which is important for wideband attenuator ladders and multi-throw RF switches operating at high frequencies.
Technically, the planar construction delivers a fast carrier response and a low forward voltage, supporting high switching speed in bias-controlled networks. The pair arrangement simplifies pi/T attenuator topologies and reduces component count and placement cost in dense RF modules.
Typical applications include RF attenuators (voltage-controlled and stepped), antenna and filter switching networks, high-voltage current control circuits, and RF resistor functions in transceiver front ends for cellular, WLAN and other wireless systems.
Design consideration: set the forward bias current according to the required RF resistance; distortion in a PIN switch decreases as forward current increases, so trade bias current against power budget. Always verify reverse-bias headroom against the 50 V rating in switched-line applications.
This page synthesizes distributor pricing, drop-in alternatives, pinout data and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for BAP70-04W,115 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:
MA4P7436ST-1146T
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RN779FT106
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RN779FFHT106
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BAP70-03W,115
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BAP70-04W,115 Maximum Ratings & Electrical Characteristics
| Diode Type | PIN - 1 pair series connection |
| Peak Reverse Voltage (VRRM) | 50 V |
| Maximum Forward Current | 100 mA |
| Total Power Dissipation | 260 mW |
| Diode Capacitance | 0.3 pF @ 20 V, 1 MHz |
| Configuration | Dual series connection (2 diodes) |
| Technology | Planar silicon PIN |
| Package | SOT-323 (SC-70) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (TR) |
| Maximum Package Power Dissipation | 260 mW |
| Application | RF attenuators, RF switching, high voltage current control |
| ECCN | EAR99 |
BAP70-04W,115 Pin Configuration
| Pin 1 | K2 β Free cathode of diode 2 (second diode in series pair) |
| Pin 2 | A1/K1 β Internal series junction: anode of diode 2 / cathode of diode 1 |
| Pin 3 | A2 β Free anode of diode 1 (first diode in series pair) |
Typical Applications
BAP70-04W,115 is suitable for 6 applications: RF Attenuators, RF Switching Networks, Wireless Transceiver Front Ends, High Voltage Current Control, RF Resistor Function, RF Test and Measurement Equipment.
RF Attenuators
The BAP70-04W,115 is purpose-built for RF attenuator circuits, exploiting the PIN diode's defining property: a forward-biased PIN diode behaves as a near-linear RF resistor whose resistance is set by DC bias current, while a reverse-biased diode contributes only 0.3 pF of capacitance at 20 V. The integrated dual-series configuration provides matched, thermally coupled diodes, which is exactly what pi-network and T-network stepped or voltage-controlled attenuators require for repeatable attenuation steps across frequency and temperature. Designers bias the diodes from a control DAC or switch-driver network; increasing forward current lowers RF resistance for deeper attenuation control. Compared with two discrete PIN diodes, the single SC-70 placement halves board area, guarantees matching, and reduces assembly cost. The 50 V rating provides headroom for high-power RF paths and reverse-biased switch states.
Recommended
RF Switching Networks
In antenna switch matrices, filter banks, and transmit/receive switch legs, the BAP70-04W,115 acts as a low-distortion, bias-controlled series element. Reverse-biased at up to 50 V, the 0.3 pF (at 20 V, 1 MHz) capacitance keeps off-state isolation high even at gigahertz frequencies; forward-biased with tens of milliamperes, the PIN pair presents low, linear series resistance that minimizes insertion loss and intermodulation - a key advantage over Schottky diodes, whose metal-semiconductor junction generates harmonics in RF paths. The dual series connection in one package suits series-element positions in SPDT/SPnT switches and switched-line phase shifters where two series diodes share a bias feed. The planar technology delivers fast carrier response for quick switching times, and the 100 mA forward current rating covers typical control currents used in medium-power RF switching applications.
Recommended
Wireless Transceiver Front Ends
Cellular, WLAN and IoT transceiver front ends use the BAP70-04W,115 for antenna diversity switching, band-select filter switching, and RX/TX path steering. The SC-70 package fits the dense layout constraints of module front ends, while the 50 V peak reverse voltage survives the RF voltage swings of transmit bursts and adjacent-channel blocking. The low forward voltage of the planar PIN technology and high switching speed support duty-cycled radio operation. Because the diode pair is matched on one die, switch legs using both halves maintain consistent insertion loss across temperature - important for meeting EVM and spectral-mask requirements. Designers should budget the control bias network carefully: too little forward current increases distortion in the transmit path, while excessive current wastes power in battery-operated IoT nodes. Typical bias currents of 10-20 mA per diode balance linearity and power consumption.
Recommended
High Voltage Current Control
Beyond pure RF use, the NXP datasheet lists high-voltage current control among the BAP70-04W's applications. The 50 V peak reverse voltage and the doubled blocking capability of the internal series pair allow the device to control signal or small power currents in circuits where a single low-voltage diode would break down. In biased control circuits - such as AGC (automatic gain control) bias steering, RF detector protection, and variable-resistance control loops - the PIN diode's resistance varies smoothly with forward current, giving analog controllability that a junction rectifier cannot provide. The 100 mA maximum forward current and 260 mW power dissipation bound the usable control range; series pair operation means the applied voltage divides across both intrinsic regions, effectively doubling safe blocking headroom versus a single PIN diode in the same bias arrangement. Verify thermal derating at elevated ambient temperatures.
Recommended
RF Resistor Function
The BAP70-04W,115 functions as an electronically variable RF resistor, the fundamental building block of gain-control and leveling circuits. When forward-biased, its series resistance is a predictable function of DC current, allowing designers to implement electronically tuned matching networks, variable equalizers, and level-setting resistors in RF amplifiers without mechanical potentiometers. The low diode capacitance of 0.3 pF at 20 V reverse bias means the element contributes minimal parasitic loading when biased off, preserving frequency response in wideband chains. Because the resistance is controlled by current rather than voltage, the control node can be located away from the RF path with proper decoupling. The matched dual-die series pair provides symmetric, repeatable resistance in balanced configurations, and the SC-70 footprint supports automated high-volume assembly in test equipment and communications hardware.
Recommended
RF Test and Measurement Equipment
Signal generators, spectrum analyzers, and automatic test equipment employ the BAP70-04W,115 in step attenuator ladders and source-switching front ends. Measurement instruments demand repeatability and low distortion: the PIN diode's linear current-controlled resistance and fast switching time enable microsecond-level attenuator step changes without relay wear or mechanical bounce, while the 0.3 pF off-capacitance preserves broadband flatness up through the gigahertz range. The matched dual-series construction reduces part-to-part variation across the instrument's attenuator decades, improving calibration stability over temperature. The 50 V reverse rating also protects control nodes during fault conditions. For instrument designers, the SC-70 footprint simplifies automated placement on dense hybrid assemblies, and the tape-and-reel ,115 packing suits volume production of modular test hardware. Confirm S-parameter and distortion data in the NXP datasheet against the target frequency band.
Recommended
Recommended Products Summary
Engineering reference data for BAP70-04W,115 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MA4P7436ST-1146T | RN779FT106 | RN779FFHT106 |
|---|---|---|---|---|
| Package | SOT-323 (SC-70) | SOT-1146 | SOT-323 (SC-70) | SOT-323 (SC-70) |
| Brand | NXP Semiconductors | MACOM Technology Solutions | Rohm Semiconductor | Rohm Semiconductor |
| Diode Configuration | 2 PIN diodes, series | PIN pair, series | PIN pair, series | PIN pair, series |
| Primary Application | RF attenuators, RF switching | RF switching / PIN attenuation | RF switching / PIN attenuation | RF switching / PIN attenuation |
Key Differentiators
- Dual-series integration halves effective capacitance (vs Single PIN diode parts)
- Genuine PIN technology, not Schottky (vs BAS70-04W (Nexperia))
- Smaller footprint than SOT-23 sibling (vs BAP70-04,115)
Design Notes
Bias current is the key design lever: a PIN diode's RF resistance falls as forward current rises, and distortion in switched RF paths decreases with higher bias. Under-biasing the BAP70-04W series pair to save power causes measurable intermodulation in transmit paths. Conversely, remember that two series diodes require roughly twice the forward voltage of a single diode at the same current - budget bias headroom accordingly. Never substitute a Schottky diode (e.g., BAS70-04W) in the PIN position; the electrical behavior is fundamentally different.
Keep RF traces to the two outer pins as short as possible and use controlled-impedance (50 ohm microstrip or CPWG) routing through the SC-70 footprint. The center series-junction pin carries the bias feed - decouple it to ground with a bypass network (e.g., 100 pF RF capacitor in parallel with a bulk capacitor) so the RF signal is not coupled into the control line. Place the reverse-bias blocking capacitor in the RF path close to the diode to minimize parasitic series inductance at gigahertz frequencies.
Estimated: the SC-70 package dissipates up to 260 mW total. With both series diodes conducting, power splits across the pair; at 100 mA forward current, total forward voltage across the series pair (per your bias circuit) times current gives dissipation - keep it below 260 mW and derate linearly above 25 C ambient per the datasheet derating curve. Grounded package pins or a small thermal pad under the SC-70 land pattern help spread heat in dense RF assemblies.
Compliance Information
Cross-reference data marks the family as halogen free. RoHS/reach status should be confirmed on the official NXP product page; the ,115 suffix denotes NXP standard RoHS-compliant tape-and-reel packing per distributor listings.
