EZ80F91AZ050EG - 8-bit 50MHz eZ80 Acclaim MCU 256KB | Zilog
MPN: EZ80F91AZ050EG ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.75 | $167.50 |
| 100 | $14.95 | $1,495.00 |
| 500 | $13.4 | $6,700.00 |
| 1,000 | $11.85 | $11,850.00 |
EZ80F91AZ050EG Overview
An 8-bit MCU (microcontroller unit) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), working memory (SRAM), and peripherals on one die. The eZ80 is a CISC (Complex Instruction Set Computer) core — a Z80-compatible architecture that retains legacy object code while extending to 24-bit linear addressing, placing it in the hierarchy: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor IC.
Key features include an integrated 10/100 Mbps Ethernet MAC (EMAC) with MII/RMII interface, a glueless external memory controller supporting SRAM/Flash/NAND/NOR, four 16-bit timers, a JTAG debug port, and 32 general-purpose I/O pins. The 50 MHz clock delivers up to 50 MIPS peak throughput — roughly 4x legacy Z80 — while preserving binary compatibility with the 1976-vintage Z80 instruction set, easing migration of installed Z80/SCC code bases.
The eZ80F91 architecture pairs a Z80-pipeline-compatible CPU with a peripheral set optimized for connected embedded nodes: PHY-less Ethernet MAC, dual UARTs with IrDA, I2C, SPI, and an interrupt controller with vectored prioritization. On-chip voltage regulation supports a 3.3 V single-supply rail; an industrial-grade operating range of -40 °C to +85 °C suits unattended enclosures.
Typical applications include point-of-sale terminals, industrial automation controllers, building-automation gateways, embedded serial-to-Ethernet bridges, and legacy Z80 retrofit designs. The combination of 16 MB linear address space and integrated EMAC positions this part as a drop-in upgrade for Z80-based systems needing TCP/IP connectivity without external NIC silicon.
When designing with the EZ80F91AZ050EG, budget the 50 MHz core supply current around 70-100 mA typical, place the 0.1 µF/10 µF decoupling network within 5 mm of each VDD/VSS pair, and use the JTAG port (not legacy Z80 monitor ROM) for in-system flash programming during production. The 144-LQFP exposed pad must be soldered to a continuous ground pour to meet thermal-resistance derating in enclosed housings.
This page synthesizes cross-distributor stock, RoHS/REACH status, and verified pin-compatible variants from the same Zilog eZ80F91 family — content not bundled in the manufacturer datasheet.
Drop-in alternatives for EZ80F91AZ050EG — 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 EZ80F91AZ050EG (same form factor and footprint) — differing in Package, UART, Core Architecture, Ethernet MAC, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
EZ80F91AZ050EC
✅ Drop-In📋 Reference alternative (not in catalog)
EZ80F92AZ050EG
✅ Drop-In📋 Reference alternative (not in catalog)
EZ80F91AZ050SC
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
EZ80F92AZ050EC
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
EZ80F91AZ050EG Maximum Ratings & Electrical Characteristics
| Core Architecture | eZ80 (Z80-compatible CISC, 24-bit linear addressing) |
| Data Bus Width | 8-bit |
| Maximum Clock Frequency | 50 MHz |
| Program Memory (Flash) | 256 KB (256K x 8) |
| SRAM | 16 KB |
| External Memory Address Space | 16 MB (24-bit linear) |
| Supply Voltage | 3.3 V |
| General-Purpose I/O | 32 |
| 16-bit Timers | 4 |
| Ethernet MAC | 10/100 Mbps EMAC with MII/RMII |
| UART | 2 (with IrDA support) |
| SPI / I2C | Yes / Yes |
| Package | 144-LQFP (20 x 20 mm) |
| Operating Temperature | -40 °C to +85 °C |
| RoHS Status | Compliant |
EZ80F91AZ050EG 144-lqfp (20 x 20 mm) Pin Configuration Guide
Pin configuration for EZ80F91AZ050EG (144-lqfp (20 x 20 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for EZ80F91AZ050EG.
Refer to the datasheet for full pin configuration.
Typical Applications
EZ80F91AZ050EG is suitable for 7 applications: Point-of-Sale (POS) Terminal, Industrial Automation Controller, Building Automation Gateway, Serial-to-Ethernet Embedded Bridge, Legacy Z80 System Retrofit, Connected Embedded Sensor Node, Embedded Communication Router.
Point-of-Sale (POS) Terminal
The EZ80F91AZ050EG fits POS terminals because its 50 MHz eZ80 core and 256 KB flash execute transaction stacks and EMV payment flows in real time. The integrated 10/100 EMAC provides TCP/IP link to back-office payment gateways without external NIC silicon, while 16 KB SRAM buffers the ISO 8583 message queues between the magnetic-stripe reader and the printer port. The 144-LQFP footprint drops onto existing Z80-based POS PCBs as a cost-effective upgrade path that retains legacy firmware call sites. The 32 GPIO are sufficient for keypad matrix, LCD interface, and cash-drawer pulse, removing the need for external I/O expanders.
Recommended
Industrial Automation Controller
The EZ80F91AZ050EG suits industrial PLC and motor-control front-ends due to its -40 °C to +85 °C operating range and 24-bit 16 MB external memory address space for large ladder-logic tables. The four 16-bit timers generate PWM and quadrature-encoder inputs for stepper and servo loops, while the dual UART (with IrDA) supports legacy RS-485 multidrop industrial field buses. Z80 binary compatibility allows re-use of decades-old control libraries. The 144-LQFP package with exposed thermal pad withstands enclosed cabinet thermal rise up to 85 °C with proper copper-pour heatsinking.
Recommended
Building Automation Gateway
The EZ80F91AZ050EG anchors BACnet/Modbus-to-IP gateways because its integrated EMAC terminates TCP/IP directly and the Z80 eZ80 core's 24-bit linear addressing maps large point-lists across 16 MB external SRAM/Flash. Two UARTs concurrently handle RS-485 (Modbus RTU) and RS-232 (BACnet MSTP) field buses, while SPI/I2C connect to local sensor hubs. Industrial -40 °C to +85 °C operation tolerates mechanical-room and rooftop enclosures. The 256 KB flash holds full TCP/IP stack, MQTT client, and BACnet/IP interpreter without external boot memory.
Recommended
Serial-to-Ethernet Embedded Bridge
The EZ80F91AZ050EG is ideal as a serial-to-Ethernet bridge because its dual UART, 50 MHz CPU, and on-chip EMAC implement the full bridge in a single IC. Legacy RS-232/RS-485 devices — barcode scanners, scales, lab instruments — gain TCP/IP connectivity for remote monitoring. The 256 KB flash holds the TCP/IP stack (Zilog's ZTP stack), HTTPS web server, and configuration UI. The 144-LQFP's exposed pad provides sufficient thermal margin at 50 MHz continuous operation within industrial enclosures.
Recommended
Legacy Z80 System Retrofit
The EZ80F91AZ050EG is a drop-in upgrade for legacy Z80-based designs because the eZ80 core is binary-compatible with the original Z80 instruction set while adding 24-bit linear addressing. Existing Z80 and Z180 object code can be re-assembled and run at up to 50 MIPS — roughly 4-10x the original Z80 at 4-10 MHz — without rewriting firmware. The 144-LQFP pinout supports common Z80 bus configurations including glueless SRAM/Flash/NOR/NAND interfacing through the on-chip external memory controller. Industrial temperature grade suits fielded retrofits.
Recommended
Connected Embedded Sensor Node
The EZ80F91AZ050EG powers TCP/IP-connected sensor hubs because its integrated EMAC, 256 KB flash, and 16 KB SRAM implement HTTP/MQTT clients in a single chip. SPI/I2C ports connect to temperature, humidity, and pressure sensors while the four 16-bit timers handle pulse-counting and PWM outputs for actuator control. Industrial -40 °C to +85 °C operation supports outdoor enclosures. The 144-LQFP footprint provides ample GPIO for multi-channel sensor aggregation without external expanders.
Recommended
Embedded Communication Router
The EZ80F91AZ050EG fits low-port-count serial routers and protocol converters because its dual UART, SPI, I2C, and integrated 10/100 EMAC form a complete bridge in one IC. 50 MHz CPU throughput processes protocol conversion (Modbus RTU to Modbus TCP, or DNP3 to TCP/IP) without external co-processors. The 256 KB flash holds full TCP/IP stack and protocol state machines; the 16 KB SRAM buffers traffic bursts. Industrial temperature grade and 144-LQFP reliability suit substation and SCADA cabinet deployments.
Recommended
Recommended Products Summary
Engineering reference data for EZ80F91AZ050EG — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | EZ80F91AZ050EC | EZ80F92AZ050EG | EZ80F91AZ050SC | EZ80F92AZ050EC |
|---|---|---|---|---|---|
| Brand | Zilog | Zilog | Zilog | Zilog | Zilog |
| Package | 144-LQFP (20x20 mm) | 144-LQFP (20x20 mm) - same | 144-LQFP (20x20 mm) - same | 144-LQFP (20x20 mm) - same | 144-LQFP (20x20 mm) - same |
| Core / Clock | eZ80 / 50 MHz | eZ80 / 50 MHz | eZ80 / 50 MHz | eZ80 / 50 MHz | eZ80 / 50 MHz |
| Flash Memory | 256 KB | 256 KB | 128 KB (-50%) | 256 KB | 128 KB (-50%) |
| SRAM | 16 KB | 16 KB | 16 KB | 16 KB | 16 KB |
| Ethernet MAC | 10/100 EMAC (MII/RMII) | 10/100 EMAC | 10/100 EMAC | 10/100 EMAC | 10/100 EMAC |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +105 °C (extended) | -40 °C to +85 °C | 0 °C to +70 °C (commercial) | -40 °C to +105 °C (extended) |
| RoHS / Lead-Free | Yes (lead-free) | Yes | Yes | Possible tin-lead (legacy) | Yes |
| Approx. Unit Price (qty 100) | USD 14.95 | USD 16.20 (extended temp) | USD 12.40 (lower flash) | USD 13.10 (commercial) | USD 13.50 |
Key Differentiators
- Industrial temperature range with lead-free RoHS finish (vs EZ80F91AZ050SC)
- Full 256 KB flash vs cost-reduced variants (vs EZ80F92AZ050EG)
- Standard industrial temperature vs extended grade (vs EZ80F91AZ050EC)
- Integrated EMAC eliminates external NIC (vs Discrete Z80 + external NIC designs)
Design Notes
The EZ80F91AZ050EG requires a single 3.3 V supply with typical core current 70-100 mA at 50 MHz plus EMAC PHY-side current. Place a 0.1 µF ceramic decoupling capacitor within 5 mm of every VDD/VSS pair and a 10 µF bulk capacitor near the supply pin. Estimated: total supply current peaks at 130 mA with the EMAC active, so budget at least 400 mA capacity from a switching regulator or LDO.
The 144-LQFP exposed thermal pad must be soldered to a continuous ground pour with at least 16 thermal vias to the inner plane to meet the datasheet thermal resistance. Without the pad soldered, junction temperature can exceed 100 °C in enclosed housings at 85 °C ambient. Estimated: with proper pad soldering, theta_JA is around 35 °C/W, allowing ~2 W continuous dissipation at 85 °C ambient.
Route the external memory bus (24-bit address, 8-bit data) with matched trace lengths and 50 Ω controlled impedance; place series damping resistors near the driver if bus length exceeds 50 mm. Keep the 50 MHz crystal traces short and symmetric, with the load capacitors placed within 3 mm of the XTAL pins. The EMAC MII/RMII traces to the external PHY should be length-matched within 25 mm to meet Ethernet timing.
Do not omit the eZ80 reset supervisor circuit — the EZ80F91 requires a minimum reset pulse width of at least 10 crystal-clock cycles. JTAG pins (TCK, TMS, TDI, TDO) must each have a 10 kΩ pull-up to VDD to prevent spurious boundary-scan activation. The flash memory write/erase cycles are rated for 100k cycles per sector; avoid unnecessary in-field reprogramming to maximize endurance.
Isolate the analog AVDD/AVSS pair (if used) from noisy digital rails with a ferrite bead or pi-filter. Place the external PHY within 50 mm of the EMAC pins and use a ground guard trace around the 50 MHz crystal to reduce radiated emissions. For EMI compliance, add a 100 pF capacitor on each clock output trace near the source to slow edge rates.
Compliance Information
RoHS compliant per Zilog product page (suffix EG denotes lead-free). EC suffix also RoHS compliant. Not AEC-Q100 qualified - the part targets industrial automation, not automotive.
