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CD4543B BCD-to-7-Segment Latch

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by Ray

BCD-to-7-segment latch/decoder/driver for LCD and LED displays, 4000B CMOS.

logicdisplay-driverbcdseven-segment4000-seriestisoic-16
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CD4543B

Texas Instruments · Display Driver · SOIC-16

The CD4543B is a BCD-to-7-segment latch, decoder, and driver for liquid-crystal and LED displays. It latches a BCD input and drives the seven segment outputs, with a phase (Ph) input that lets it drive LCDs directly from a backplane square wave or LEDs with a fixed level. A blanking input turns all segments off.

Pinout

Pin Name Type Function
1 LD input Latch Disable. When LD=1 the BCD inputs A-D are transparent to the decoder; when LD=0 the last BCD code is stored and the display is frozen. Minimum latch-disable pulse width tWH = 125 ns typ at VDD=5 V.
2 C input BCD data input, weight 2^2 (bit 2). CMOS input with typ 5 pF input capacitance; VIH/VIL = 3.5/1.5 V at VDD=5 V.
3 B input BCD data input, weight 2^1 (bit 1). CMOS input, latched by LD.
4 D input BCD data input, weight 2^3 (MSB). CMOS input, latched by LD.
5 A input BCD data input, weight 2^0 (LSB). CMOS input, latched by LD.
6 PHASE input Phase / Ph input. Selects the polarity of the seven-segment outputs. For LCD drive, apply a square wave (common-plane signal). For common-cathode LEDs tie Ph=0; for common-anode LEDs tie Ph=1.
7 BLANKING input Blanking (BI) input. When BI=1 all seven segment outputs are forced to the inactive state (display blanked). When BI=0 the decoded pattern (XOR'd with Ph) is presented on a-g. Tie to VSS for a pin-compatible replacement of the CD4056B.
8 VSS power_in Negative supply / ground reference. Voltage range 0 V; all input/output voltages are referenced to VSS.
9 a output Seven-segment output 'a'. CMOS push-pull driver; capable of driving two low-power TTL loads, two HTL loads, one low-power Schottky load, LCD segment (via square-wave Ph) or LED segment directly. IOL/IOH ~1 mA typ at VDD=5 V.
10 b output Seven-segment output 'b'. CMOS push-pull segment driver, same characteristics as segment a.
11 c output Seven-segment output 'c'. CMOS push-pull segment driver.
12 d output Seven-segment output 'd'. CMOS push-pull segment driver.
13 e output Seven-segment output 'e'. CMOS push-pull segment driver.
14 g output Seven-segment output 'g' (center bar). CMOS push-pull segment driver.
15 f output Seven-segment output 'f'. CMOS push-pull segment driver.
16 VDD power_in Positive supply. Recommended VDD-VSS = 3 V to 18 V (absolute maximum 20 V). Quiescent IDD 0.04 µA typ at VDD=5 V.

Key specifications

Parameter Value
Type BCD-to-7-segment latch / decoder / driver
Logic family 4000B (CMOS)
Display types LCD (with phase input) or LED
Features Latch, ripple blanking, phase input
Supply voltage 3 V to 18 V
Operating temperature -55 C to 125 C

Ordering variants

Same part, different packaging or reel option.

  • CD4543BE
  • CD4543BM
  • CD4543BM96
  • CD4543BNSR
  • CD4543BPW
  • CD4543BPWR
  • CD4543BMT

CAD (KiCad official)

  • Symbol: cd4543.kicad_sym
  • Footprint: cd4543.kicad_mod
  • 3D model: SOIC-16 body from KiCad Package_SO/SOIC-16_3.9x9.9mm_P1.27mm.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: Texas Instruments datasheet (20 pp, sha256 a1121ae23a462a55, retrieved 2026-08-17, tier: manufacturer)
  • Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF