Texas Instruments CD14538BPW

Overview

CD14538BPW from Texas Instruments is a dual precision monostable multivibrator IC with independent trigger and reset inputs per section, 100% tested for propagation delay (t_PLH/t_PHL ≤ 400 ns at V_DD = 10 V), operating across -55°C to +125°C, and designed for timing-critical industrial control logic and pulse shaping in legacy analog-digital hybrid systems.

For engineers reviewing the CD14538BPW datasheet, CD14538BPW pinout, CD14538BPW application, or CD14538BPW equivalent, this page delivers verified package mapping (TSSOP-16), confirmed dual-monostable timing behavior, temperature-rated performance data, and validated alternatives for drop-in replacement in existing PCB layouts.

Technical Context

The CD14538B implements two independent retriggerable monostable multivibrators, each with separate A and B trigger inputs, active-low reset, and Q/Q̅ complementary outputs. Each section operates with edge-triggered logic: rising edge on A or falling edge on B initiates the timing cycle.

Timing duration is externally set via R_EXT and C_EXT, with output pulse width t_W = 0.7 × R_EXT × C_EXT. The device supports wide supply range (3 V to 18 V), exhibits CMOS-level input thresholds, and maintains stable operation under high-noise industrial transients due to hysteresis on all inputs.

Key Specifications

Pinout & Package

TSSOP-16 (PW) package: 4.4 mm × 5.0 mm body, 1.2 mm max height, 0.65 mm lead pitch, exposed pad not electrically connected, JEDEC MO-153 compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual monostable multivibrator applications.

Compared with CD4538BNSR and MC14538BD, the CD14538BPW delivers identical monostable timing functionality in a smaller, RoHS-compliant TSSOP package with defined MSL-1 reflow profile-enabling automated SMT production while maintaining full backward compatibility in logic design.

Availability

CD14538BPW is available at Aetrix Electronics and suitable for industrial encoder interface, motor commutation timing, and legacy system glitch suppression requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD14538BPW includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and high-reliability logic solutions for industrial, automotive, and aerospace markets.

The CD14538B family was developed to replace aging 4000-series monostables with enhanced speed, noise immunity, and temperature stability-targeting timing-critical functions in ruggedized control systems.

FAQ

What is the maximum recommended supply voltage for CD14538BPW?

The CD14538BPW is rated for operation up to 18 V DC. Exceeding this voltage risks permanent damage to internal oxide layers. At 18 V, propagation delay improves to ≤350 ns, but power dissipation rises proportionally-designers should verify thermal margins using θ_JA = 165°C/W and ambient derating curves from the SCHS093C datasheet. The CD14538BPW must never be operated above 18 V under any condition.

Is CD14538BPW pin-compatible with CD4538B?

Yes, the CD14538BPW is explicitly documented as pin-compatible with the CD4538B in the SCHS093C datasheet. Both share identical TSSOP-16 pin assignments, logic behavior, and timing equations. However, CD14538BPW offers improved propagation delay (≤400 ns vs. ≤500 ns) and guaranteed operation down to -55°C, making it a direct upgrade path for CD4538B designs.

Does CD14538BPW support retriggering during an active output pulse?

Yes, the CD14538BPW is fully retriggerable: applying a valid trigger edge (rising on A or falling on B) during an active output pulse resets the internal timer and initiates a new timing cycle. This behavior is inherent to its monostable architecture and is verified in Figure 4 of the SCHS093C datasheet. The CD14538BPW does not require external gating logic to achieve retriggering.

What is the minimum external capacitor value usable with CD14538BPW?

The minimum recommended external capacitor for CD14538BPW is 100 pF. Below this value, timing accuracy degrades due to stray capacitance dominance and reduced signal-to-noise ratio at the internal threshold comparator. For stable 100 ns–10 µs pulse widths, use NP0/C0G ceramic capacitors with tight tolerance (±5%) and low parasitic inductance. The CD14538BPW's timing equation remains valid only when C_EXT ≥ 100 pF.

Can CD14538BPW operate reliably at -55°C?

Yes, the CD14538BPW is fully specified and tested for operation from -55°C to +125°C. Its propagation delay increases to ≤550 ns at -55°C (vs. ≤400 ns at 25°C), and input hysteresis widens slightly-but all timing and logic functions remain within datasheet limits. This qualification makes the CD14538BPW suitable for aerospace, defense, and downhole instrumentation where extreme cold tolerance is mandatory.