CD4520BF3A Texas Instruments Integrated Circuit (Ceramic Dual-In-Line Packages) In Stock
CD4520BF3A is a dual 4-bit binary up-counter in the CMOS 4000-series logic family from Texas Instruments, featuring gated clock inputs and a Schmitt trigger on each clock input for noise immunity. Each of the 2 independent counter sections counts from 0 to 15 and is housed in a 16-pin ceramic DIP package rated for industrial and military temperature ranges. Available worldwide from stock with global shipping.
- Manufacturer
- Texas Instruments
- Package
- Ceramic Dual-In-Line Packages
- Pin Count
- 16
- Lifecycle
- ACTIVE
- Datasheet
- CD4520BF3A Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $21.3198(MOQ 25)
- Temp Range
- -55.0°C to 125.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What are the key features of CD4520BF3A?
- Dual independent 4-bit binary up-counter with gated clock inputs allows cascading to 8-bit or wider counting without external logic, doubling counting depth in a single 16-pin package
- Schmitt trigger on each clock input provides hysteresis for reliable counting from slow or noisy clock edges, eliminating false counts in electrically noisy industrial and military environments
- Ceramic DIP (CDIP) package with 50 pF rated load capacitance suits high-reliability military and industrial applications where plastic DIP moisture sensitivity and thermal cycling resistance are not acceptable
What is CD4520BF3A used for?
CD4520BF3A is used in legacy and high-reliability digital systems as a frequency divider or event counter, where its dual 4-bit sections can be cascaded into 8-bit counters by connecting the carry-out of one section to the clock of the next. Military avionics and satellite instrumentation boards favor the ceramic DIP package for its hermetic-equivalent reliability over extended temperature ranges beyond the -55°C to +125°C specification. Industrial process control systems also use this device for pulse counting, position encoding, and timer sequencing where the Schmitt trigger clock input ensures glitch-free operation in environments with inductive switching noise.
What are the specifications of CD4520BF3A?
| Pbfree Code | Yes |
| YTEOL | 15 |
| Additional Feature | GATED CLOCK; SCHMITT TRIGGER ON CLOCK INPUT |
| Count Direction | UP |
| Family | 4000/14000/40000 |
| JESD-30 Code | R-GDIP-T16 |
| JESD-609 Code | e0 |
| Load Capacitance (CL) | 50pF |
| Load/Preset Input | NO |
| Logic IC Type | BINARY COUNTER |
| Max Frequency@Nom-Sup | 1500000Hz |
| Max I(ol) | 0.0015A |
| Mode of Operation | SYNCHRONOUS |
| Number of Bits | 4 |
| Number of Functions | 2 |
| Package Body Material | CERAMIC, GLASS-SEALED |
| Package Equivalence Code | DIP16,.3 |
| Package Shape | RECTANGULAR |
| Package Style | IN-LINE |
| Packing Method | TUBE |
| Power Supply Current-Max (ICC) | 0.03mA |
| Prop. Delay@Nom-Sup | 230ns |
| Propagation Delay (tpd) | 560ns |
| Qualification Status | Not Qualified |
| Screening Level | 38535Q/M;38534H;883B |
| Supply Voltage-Max (Vsup) | 18V |
| Supply Voltage-Min (Vsup) | 3V |
| Supply Voltage-Nom (Vsup) | 5V |
| Surface Mount | NO |
| Technology | CMOS |
| Temperature Grade | MILITARY |
| Terminal Finish | Tin/Lead (Sn/Pb) |
| Terminal Form | THROUGH-HOLE |
| Terminal Pitch | 2.54mm |
| Terminal Position | DUAL |
| Trigger Type | POSITIVE EDGE |
| fmax-Min | 4MHz |
| Package | Ceramic Dual-In-Line Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.90 |
Where can I find the CD4520BF3A datasheet?
CD4520BF3A Datasheet DownloadOfficial datasheet from Texas Instruments
What are equivalent replacements for CD4520BF3A?
Compatible alternatives and drop-in replacements for CD4520BF3A:
Binary Counter, 4000/14000/40000 Series, Synchronous, Positive Edge Triggered, 4-Bit, Up Direction, CMOS, CDIP16
Binary Counter, 4000/14000/40000 Series, Synchronous, Positive Edge Triggered, 4-Bit, Up Direction, CMOS, PDIP16
Binary Counter, 4000/14000/40000 Series, Synchronous, Positive Edge Triggered, 4-Bit, Up Direction, CMOS, PDIP16
Frequently Asked Questions
How can two CD4520BF3A counter sections be cascaded to achieve 8-bit counting range?
Each CD4520BF3A contains 2 independent 4-bit binary up-counters that count from 0 to 15 (4-bit full range). By connecting the carry-out pin (Q4) of the first 4-bit section to the clock input (CLOCK) of the second section within the same package, the designer creates a synchronous 8-bit counter with a range of 0 to 255. For wider counters, a second CD4520BF3A can extend this to 16-bit counting (0 to 65535) by cascading the carry output of the second device's second counter into the next stage.
Why does the Schmitt trigger clock input of CD4520BF3A matter in an industrial control panel application?
In industrial panels near variable frequency drives, relay coils, and solenoids, clock signals can exhibit slow rise times and superimposed noise spikes. The Schmitt trigger on the CD4520BF3A clock input applies hysteresis — typically 1 V to 2 V of threshold difference at a 5 V supply — so the counter only increments on a definitive positive or negative clock transition, ignoring noise excursions that do not cross the hysteresis band. This prevents false count increments that would corrupt position feedback or timing sequences in PLCs and motion controllers.
What supply voltage range does CD4520BF3A support, and how does it interface with TTL logic levels?
As a member of the CMOS 4000 family, CD4520BF3A operates across a wide supply voltage range of 3 V to 15 V, providing significant flexibility. At 5 V it is nominally TTL output-compatible, though its input thresholds at 5 V (VIH ≈ 3.5 V, VIL ≈ 1.5 V) differ from standard TTL, so a TTL-to-CMOS input buffer may be needed for reliable interfacing. At 10 V or 15 V the device achieves better noise immunity and faster switching at the 50 pF rated load capacitance.
For a military system upgrade, when is CD4520BF3A preferred over a surface-mount CMOS counter?
CD4520BF3A is preferred in military system upgrades where the existing PCB uses through-hole ceramic DIP sockets, enabling drop-in replacement without PCB redesign, rerouting, or new tooling. The ceramic DIP (R-GDIP-T16) package provides better hermetic sealing against moisture and contaminants than plastic SMD packages, and its -55°C to +125°C operating range meets MIL-SPEC temperature grade requirements for airborne and ground vehicle electronics. Programs with long service lives also benefit from the 4000 series' established supply chain and multi-decade production history.
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About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
More from Texas Instruments
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 25+ | $23.7280 | $593.20 |
| 100+ | $22.0970 | $2209.70 |
| 250+ | $21.3198 | $5329.94 |
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