Microchip Technology CD823A

Overview

CD823A from Microsemi is a monolithic temperature-compensated zener reference diode with nominal zener voltage 5.9–6.5 V, 7.5 mA test current, 13 Ω dynamic impedance at 25°C, ±0.005 %/°C effective temperature coefficient, and rated for -65°C to +175°C operation - used in precision voltage references for aerospace power supplies and high-reliability analog instrumentation.

For engineers reviewing the CD823A datasheet, CD823A pinout, CD823A application, or CD823A equivalent, key selection criteria include zener voltage tolerance, low-temperature-coefficient stability across military temperature ranges, low dynamic impedance under 7.5 mA bias, and compatibility with wire bonding and conductive die attach (excluding solder reflow).

Technical Context

The CD823A implements a monolithic silicon zener structure with full silicon dioxide junction passivation, enabling stable reverse-biased operation over extreme temperatures. Its zener voltage is specified at 7.5 mA test current with 48 mV maximum voltage drift from -55°C to +100°C.

It features an effective temperature coefficient of ±0.005 %/°C and exhibits 13 Ω zener impedance (ZZT) measured using 10% 60 Hz AC superimposed on DC bias - confirming suitability for low-noise, high-stability reference applications where thermal drift must be minimized.

Key Specifications

Pinout & Package

CD823A is supplied as a bare die in a rectangular silicon chip with three metallized terminals: Cathode (Terminal 1), Anode (Terminal 2), and non-functional test pad (Terminal 3). Backside is gold-plated and electrically isolated; cathode must be biased positive relative to anode for zener operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar zener reference applications.

Compared with CD825A and CD827A, the CD823A delivers optimal balance of low impedance (13 Ω), proven military qualification, and cost-effective stability (±0.005 %/°C) - making it preferred for aerospace power management and industrial instrumentation where 10 ppm/°C reference drift is acceptable.

Availability

CD823A is available at Aetrix Electronics and suitable for aerospace power supplies, downhole instrumentation, avionics analog front-ends, and military data acquisition systems requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for CD823A 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

Microsemi Corporation (now part of Microchip Technology) designs high-reliability analog and mixed-signal semiconductors for aerospace, defense, and industrial markets.

The CD823A belongs to Microsemi's qualified monolithic zener reference die family, engineered specifically for precision voltage referencing in extreme-temperature, high-reliability systems where MIL-PRF-19500/159 compliance is mandatory.

FAQ

What is the zener voltage range of the CD823A?

The CD823A has a zener voltage range of 5.9 V to 6.5 V, measured at a test current of 7.5 mA and ambient temperature of 25°C. This range reflects manufacturing tolerance and ensures interchangeability within the CD82xA series while maintaining compatibility with legacy 1N821–1N829 designs. The CD823A's voltage is guaranteed to fall within this band under all qualified operating conditions.

Is the CD823A compatible with solder reflow assembly?

No, the CD823A is explicitly incompatible with solder reflow processes due to its aluminum metallization and die construction. Per LDS-0052 Rev. 1, it is qualified only for wire bonding and conductive die attach techniques. Using solder reflow risks metallurgical degradation and parametric shift. The CD823A must be mounted using epoxy or conductive adhesive followed by thermosonic or ultrasonic wire bonding.

What does the "A" suffix indicate in CD823A?

The "A" suffix in CD823A denotes qualification to JANKC level per MIL-PRF-19500/159 - indicating enhanced screening including burn-in, temperature cycling, and hermeticity testing beyond baseline JANHC. This version provides improved lot-to-lot consistency and longer qualification life, making CD823A suitable for programs requiring extended reliability documentation and traceability.

How does the CD823A achieve its low temperature coefficient?

The CD823A achieves ±0.005 %/°C effective temperature coefficient through monolithic integration of complementary zener and forward-biased junctions that cancel thermal drift across -55°C to +100°C. Unlike discrete compensation networks, this on-die architecture eliminates matching errors and aging effects - a design feature confirmed in LDS-0052 Figure 3 and verified across qualified lots.

Can the CD823A replace a 1N823 in existing designs?

Yes, the CD823A is electrically equivalent to the 1N823 per LDS-0052, sharing identical zener voltage range (5.9–6.5 V), test current (7.5 mA), and dynamic impedance (13 Ω). However, as a bare die versus TO-5 can package, mechanical integration differs - users must adapt mounting, bonding, and isolation methods. The CD823A offers improved tempco (±0.005 %/°C vs. typical ±0.01 %/°C for 1N823) and extended temperature rating.