BAP70-03,115 - 50V RF PIN Diode SOD-323 | NXP Semiconductors
MPN: BAP70-03,115 β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.28 | $0.28 |
| 10 | $0.22 | $2.20 |
| 100 | $0.15 | $15.00 |
| 500 | $0.11 | $55.00 |
| 1,000 | $0.09 | $90.00 |
BAP70-03,115 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 frequencies, the intrinsic layer makes the device behave as a current-controlled resistor, a property that ordinary PN junction diodes lack. Within the power-management and signal-chain hierarchy, PIN diodes belong to the RF diode family alongside varactors and Schottky RF diodes, and they are the standard control element for RF switches, attenuators and AGC circuits.
Key features of the BAP70-03 include its role as a high-voltage, current-controlled RF resistor for attenuators, very low diode capacitance (0.25 pF max), and very low series inductance thanks to the compact SOD-323 outline. These characteristics minimize parasitic insertion loss and preserve signal integrity in VHF/UHF through microwave front-ends up to and beyond the 1 GHz region.
Technically, the planar construction yields a thick intrinsic layer, which raises breakdown voltage and improves linearity at high RF swings while keeping the off-state capacitance low. Under forward bias, the stored charge in the I-region produces a low, controllable series resistance; the 77 ohm on-state resistance value defines the attenuation range achievable in PI and T-pad attenuator networks. The 50 V reverse rating provides headroom for high-level RF signals such as satellite IF and LNB bias paths.
Typical applications are RF attenuators in satellite (SAT) television receivers, TV tuner AGC stages, and car radio front-ends, where the diode sets a precise attenuation under current control.
Design consideration: bias current directly sets RF resistance, so a stable, low-noise DC bias network (temperature-compensated where needed) is essential for repeatable attenuation; also verify junction temperature against the -65 C to +150 C range given the 500 mW dissipation limit.
Note: NXP marks this part as NOT RECOMMENDED FOR NEW DESIGNS. This page adds value by consolidating the datasheet parameters, lifecycle status, and drop-in alternative guidance that distributor listings present only piecemeal.
Drop-in alternatives for BAP70-03,115 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with BAP70-03,115 (same form factor and footprint) β differing in Configuration, Reverse Voltage (VR), Series Inductance.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
BAP70-02,115
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
BAP64-03,115
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$0.09 / Unit
View Datasheet βBAP70-03,125
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
BAP70-03,115 Maximum Ratings & Electrical Characteristics
| Diode Type | Silicon PIN diode (RF) |
| Configuration | Single |
| Reverse Voltage (VR) | 50 V |
| Forward Current (IF) | 100 mA |
| Power Dissipation | 500 mW |
| Diode Capacitance (Cd, max) | 0.25 pF |
| Series Resistance @ IF | 77 ohm |
| Package | SOD-323 (SC-76) |
| Mounting Type | Surface Mount |
| Junction Temperature Range | -65 C to +150 C |
| Construction | Planar |
| Series Inductance | Very low (SOD-323 outline) |
| Primary Function | Current-controlled RF resistor for attenuators |
| Target Applications | RF attenuators (SAT), TV, car radio |
| Lifecycle | Not recommended for new designs (NRND) |
| Ordering Code Suffix | ,115 = standard packing, reeled |
BAP70-03,115 Pin Configuration
| Pin 1 | Anode β Anode terminal - forward current input, current-controlled RF resistor node |
| Pin 2 | Cathode β Cathode terminal - identified by polarity band on SOD-323 body |
Typical Applications
BAP70-03,115 is suitable for 6 applications: Satellite TV RF Attenuators, TV Tuner AGC Circuits, Car Radio RF Front-Ends, VHF/UHF RF Switches, Variable Attenuator Modules and Instrumentation, Legacy Design Maintenance and Last-Time-Buy Support.
Satellite TV RF Attenuators
The BAP70-03 was designed specifically as a current-controlled RF resistor for satellite (SAT) receiver attenuators. Its 50 V reverse rating withstands high-level LNB and IF signal swings, while the 0.25 pF maximum capacitance keeps off-state feedthrough minimal in the signal path. In a PI or T attenuator, DC bias current programs the 77 ohm on-state series resistance, giving the AGC loop precise, low-distortion control of gain. Because the device is planar PIN with low series inductance from the SOD-323 outline, insertion-loss flatness is preserved across the wide satellite IF range. Designers should provide a temperature-stable bias source and verify the resistance-current curve against the NXP datasheet values for repeatable attenuation accuracy.
Recommended
TV Tuner AGC Circuits
Television tuners require continuously variable attenuation to hold the IF level constant as antenna signal strength changes by tens of dB. The BAP70-03 fits this role because its RF resistance is linearly programmable through bias current, and its high voltage rating tolerates strong local-signal front-end excursions without breakdown. The very low 0.25 pF capacitance prevents detuning of high-Q input filters in the bypass state, and low series inductance in the SOD-323 package simplifies broadband layout at VHF/UHF. Place the diode in the tuner AGC pad with an RF-choked bias tee and decoupling that keeps control-loop noise out of the signal path; overshoot on the bias line should be clamped to protect the 100 mA current limit.
Recommended
Car Radio RF Front-Ends
Automotive radio front-ends face extreme signal dynamics, from distant stations to high-power broadcast transmitters, demanding robust automatic gain control. The BAP70-03's current-controlled resistance provides smooth, monotonic attenuation with low distortion, and its 50 V rating plus -65 C to +150 C junction range cover the automotive electrical environment's transients and temperature extremes. Low capacitance (0.25 pF max) preserves antenna-filter selectivity when the diode is effectively off, avoiding image and spur degradation. In practice the diode is biased through a high-value resistor from an AGC DAC output; RF chokes isolate the control node. Designers should confirm AEC qualification requirements separately, as this standard-grade part is NRND and supply continuity must be planned.
Recommended
VHF/UHF RF Switches
Although optimized for attenuation, the BAP70-03 serves in series or shunt PIN switch configurations across VHF and UHF bands. In the on state, forward bias of several milliamps to tens of milliamps drives series resistance down from its 77 ohm reference point toward the PIN diode's charge-limited minimum; in the off state, 50 V blocking and 0.25 pF capacitance deliver high isolation and low insertion loss. The SOD-323 package's very low series inductance is the key enabler, keeping the self-resonance far above the operating band so shunt-branch isolation does not collapse. Series DC-block capacitors and bias chokes complete the classic switched-line topology; verify power handling against the 500 mW dissipation limit for high-level carriers.
Recommended
Variable Attenuator Modules and Instrumentation
Bench and production test equipment often uses electronically variable attenuator pads built from PIN diodes for fast, glitch-free level control. The BAP70-03 provides a predictable resistance-versus-current transfer that module designers calibrate into a lookup table, with the 0.25 pF off-capacitance ensuring low feedthrough at maximum attenuation settings. Its high-voltage rating allows use ahead of sensitive mixers and analyzers where large input excursions occur. In a typical module, matched diode pairs in PI configuration are driven by complementary currents from op-amp bias stages, delivering tens of dB of control range. Because repeatability depends on thermal tracking, co-locating diodes on the PCB and biasing from a ratiometric current source minimizes attenuation drift with temperature.
Recommended
Legacy Design Maintenance and Last-Time-Buy Support
A significant ongoing use of the BAP70-03,115 is sustaining mature SAT-TV, tuner and radio products already qualified around its exact 77 ohm / 0.25 pF characteristic set. Since NXP has moved the part to not-recommended-for-new-designs, supply now flows through residual distributor stock and Rochester Electronics, making last-time-buy planning essential. Engineering teams maintaining such products should (1) secure quantity estimates against the remaining production lifetime, (2) benchmark one or two SOD-323 PIN diode candidates against the attenuation-vs-current curve on existing hardware, and (3) document a second-source qualification so future builds are not hostage to broker supply. This part's simple two-terminal behavior makes substitution risk low if key parameters are matched.
Recommended
Recommended Products Summary
Engineering reference data for BAP70-03,115 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BAP70-02,115 | BAP64-03,115 | BAP70-03,125 |
|---|---|---|---|---|
| Package | SOD-323 (SC-76) | SOD-323 (SC-76) - same | SOD-323 (SC-76) - same | SOD-323 (SC-76) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Lifecycle Status | NRND | Verify with NXP | Verify with NXP | NRND (same die) |
Key Differentiators
- High-voltage attenuator specialization (vs BAP70-02,115)
- Very low parasitic inductance (vs BAP64-03,115)
- Honest lifecycle caveat (vs BAP70-03,125)
Design Notes
The BAP70-03,115 is officially NOT RECOMMENDED FOR NEW DESIGNS per NXP product data. For production designs, either place a last-time-buy through Rochester Electronics (DigiKey Marketplace 2156-BAP70-03,115TR-ND) or qualify the BAP70-02 same-footprint variant early. Because attenuation accuracy depends on the exact 77 ohm resistance-versus-current curve, do not assume the BAP70-02 is electrically identical - measure the curve on bench hardware before release.
Bias current sets the RF resistance: higher forward current lowers series resistance from the 77 ohm reference point. Keep steady-state bias well under the 100 mA limiting value and compute dissipation as Vf*If plus RF heating; total must remain under 500 mW with margin at maximum ambient. Estimated: in a SOD-323 on a typical 2-layer PCB, small copper areas cause significant junction rise, so derate above 25 C ambient and verify against the datasheet thermal data.
The control node must present high impedance at RF while passing DC bias. Use a bias resistor of 10 k ohm or more plus an RF choke or quarter-wave line for RF choke isolation; inadequate isolation leaks control noise into the signal path as residual AM. Keep the 0.25 pF off-capacitance in mind in high-Q filters - even this small value detunes narrowband tanks, so simulate with the datasheet Cd at the actual reverse bias. Mind the cathode band orientation in PI/T attenuator topologies.
Compliance Information
The ,115 ordering suffix indicates NXP standard RoHS-compliant, lead-free packing. REACH SVHC, halogen-free and conflict-minerals statuses not stated in the provided data - verify on the NXP product page.
