ATSHA204A-MAHDA-T - SHA-256 CryptoAuthentication IC | Microchip
MPN: ATSHA204A-MAHDA-T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.55 | $5.50 |
| 100 | $0.44 | $44.00 |
| 500 | $0.38 | $190.00 |
| 1,000 | $0.33 | $330.00 |
| 3,000 | $0.29 | $870.00 |
ATSHA204A-MAHDA-T Overview
A cryptographic authentication IC is a specialized security chip that stores secret keys in protected memory and performs challenge-response computations entirely on-chip, so secrets never appear on an external bus. Within the system hierarchy, it sits below the main processor as a security co-processor, complementing microcontrollers, memory ICs, and power management ICs in an embedded design. The ATSHA204A belongs to Microchip's CryptoAuthentication family, which the manufacturer positions as its most cost-effective hardware authentication solution.
Key features include hardware SHA-256 computation, a 4.5Kb EEPROM organized as 16 zones supporting key storage, read-only data, consumption logging, and security configuration, and a flexible command set. The chip also integrates an SHA-256 HMAC/PRF engine, random number generation support, and diverse attack-protection mechanisms such as active shield overlays and key access controls defined by configuration fuses.
Technically, the device is a CMOS authenticator whose command interpreter processes Authenticate, Read, Write, DeriveKey, and MAC commands. Because key storage, hashing, and comparison occur inside the die, board-level probes cannot intercept secrets, addressing the fundamental weakness of software-only authentication. The shared-bus Single-Wire mode allows multiple ATSHA204A devices on one processor pin, useful for consumable identification such as ink tanks or spare parts.
Typical applications include clone prevention for spare parts and consumables, secure firmware boot authentication, secure network node identity, and consumable lifecycle tracking. The MAHDA-T variant specifically supports the I2C interface, making it a natural companion for microcontrollers and FPGA hosts.
Design consideration: configure the IO interface (Single-Wire versus I2C) and zone access policies before fusing the configuration zone, as these settings are permanent and directly determine key protection strength.
This page synthesizes verified distributor data, drop-in alternatives, pinout guidance, and practical design notes that are not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATSHA204A-MAHDA-T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSHA204A-MAHDA
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATSHA204-MAH-DA-T
✅ Drop-In📋 Reference alternative (not in catalog)
ATECC508A-MAHTN-T
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATECC608A-MAHTN-T
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATSHA204A-MAHDA-T Maximum Ratings & Electrical Characteristics
| Device Type | Cryptographic Authentication IC |
| Algorithm | SHA-256 (NIST) |
| EEPROM Density | 4.5 Kb |
| Key Size | 256 bit |
| EEPROM Organization | 256 x 16 |
| Number of Zones | 16 |
| Interface Type | Single-Wire; I2C |
| Operating Voltage | 2 V to 4.5 V |
| Typical Operating Current | 0.5 mA |
| Operating Temperature Range | -40C to +85C |
| Package | 8-UDFN (2x3 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (T/R) |
| Memory Type | EEPROM, Serial - I2C |
| Technology | CMOS |
ATSHA204A-MAHDA-T Pin Configuration
| Pin 1 | SDA — I2C serial data (per datasheet, IO pin) |
| Pin 2 | VCC — Power supply, 2 V to 4.5 V |
| Pin 3 | NC — No connect (per datasheet) |
| Pin 4 | NC — No connect (per datasheet) |
| Pin 5 | SCL — I2C serial clock (per datasheet) |
| Pin 6 | GND — Ground |
| Pin 7 | NC — No connect (per datasheet) |
| Pin 8 | NC — No connect (per datasheet) |
Typical Applications
ATSHA204A-MAHDA-T is suitable for 6 applications: Clone Prevention and Secure Boot, Consumable and Spare Part Authentication, Network and IoT Node Identity, Secure Firmware Intellectual Property Protection, Medical Consumable Tracking, Battery Pack Authentication.
Clone Prevention and Secure Boot
The ATSHA204A-MAHDA-T anchors secure boot and anti-cloning schemes: a 256-bit secret key stored in its 4.5Kb EEPROM computes an SHA-256 response to a host challenge entirely on-chip, so the key never appears on the I2C bus. Placed on the I2C rail of the main processor at 3.3 V, the host authenticates the board before executing firmware. Because hashing and key comparison occur inside the die, probing attacks cannot extract credentials, and the 16-zone memory permits separate keys for boot, firmware updates, and accessory validation. This makes it a low-cost (~$0.30 at 1000 pieces) alternative to more expensive secure elements where symmetric authentication suffices.
Recommended
Consumable and Spare Part Authentication
OEM consumables such as ink tanks, batteries, medical probes, and industrial spare parts are authenticated with an ATSHA204A-MAHDA-T embedded in each cartridge or module. The Single-Wire interface lets multiple authenticators share one host GPIO pin, so a printer validating four color tanks uses only one processor pin total, as described in the Microchip datasheet sharing-the-interface section. Each consumable carries a unique 256-bit key; the host rejects clones with a failed challenge-response. Typical active current of 0.5 mA and automatic sleep keep the load on the cartridge cell negligible, extending consumable shelf life.
Recommended
Network and IoT Node Identity
IoT and networked nodes use the ATSHA204A-MAHDA-T to generate and protect device identity data: the 4.5Kb EEPROM stores per-device serial numbers, certificates-adjacent data, and rotation keys, while the NIST SHA-256 engine produces hashed node identities for cloud onboarding. Operating from a 2 V to 4.5 V rail suits battery- and coin-cell-powered sensors; sleep-mode operation between authentications preserves energy budget. The 8-UDFN 2x3 mm footprint fits dense sensor PCBs, and the exposed pad simplifies grounding. Firmware teams integrate it with Microchip CryptoAuthentication libraries on common MCU stacks.
Recommended
Secure Firmware Intellectual Property Protection
Equipment vendors protect firmware IP by encrypting images and binding the decryption check to an ATSHA204A-MAHDA-T: the bootloader hashes the encrypted image with an on-chip key and refuses execution on mismatch. Because the 16 zones can separate the IP-protection key from field-service keys, contract manufacturers can flash boards without access to the vendor's root secret. The -40C to +85C industrial rating and CMOS construction support factory-floor programmers. Configuring zone access policies before fusing is the critical design step, since configuration writes are permanent.
Recommended
Medical Consumable Tracking
Medical diagnostic systems authenticate single-use cartridges and track usage with the ATSHA204A-MAHDA-T's consumption-logging EEPROM capability. Each disposable stores a secret and a usage counter; the analyzer verifies authenticity and refuses expired or counterfeit cartridges, supporting patient-safety and regulatory documentation goals. The 2 V to 4.5 V supply range integrates with low-voltage analyzer electronics, and the -40C to +85C range covers sterilization-adjacent storage conditions. On-chip SHA-256 computation keeps the authentication latency at the millisecond level over I2C, invisible to the operator.
Recommended
Battery Pack Authentication
Power-tool and drone battery packs embed an ATSHA204A-MAHDA-T so chargers and hosts validate the pack before enabling charge or discharge. A 256-bit challenge-response over the pack's I2C bus confirms a genuine cell assembly, protecting revenue and preventing hazardous counterfeit packs from operating. The authenticator's 0.5 mA typical active draw is negligible versus pack management current, and sleep mode eliminates standby drain during storage. The 8-UDFN (2x3 mm) package withstands vibration-dominated environments, and the -40C to +85C rating matches outdoor battery operating windows.
Recommended
Recommended Products Summary
Engineering reference data for ATSHA204A-MAHDA-T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSHA204A-MAHDA | ATSHA204-MAH-DA-T | ATECC508A-MAHTN-T | ATECC608A-MAHTN-T |
|---|---|---|---|---|---|
| Package | 8-UDFN (2x3 mm) EP | 8-UDFN (2x3 mm) EP - same | 8-UDFN (2x3 mm) EP - same | 8-UDFN (2x3 mm) EP - same | 8-UDFN (2x3 mm) EP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Algorithm | SHA-256 | SHA-256 | SHA-256 | ECDSA + SHA-256 | ECDSA + SHA-256 |
| Interface | I2C (MAHDA variant) | I2C | Single-Wire; I2C | I2C / Single-Wire | I2C / Single-Wire |
| Operating Voltage | 2 V to 4.5 V | 2 V to 4.5 V | 2 V to 4.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Lifecycle Status | Active | Active | Legacy (predecessor) | Active | Active |
| Relative Cost | Lowest cost in CryptoAuth portfolio | Same die | Comparable | Higher | Higher |
Key Differentiators
- Lowest-cost hardware authentication in Microchip's CryptoAuthentication portfolio (vs ATECC608A-MAHTN-T)
- Shared-bus Single-Wire option across the family (vs ATSHA204-MAH-DA-T)
- Trade-off: symmetric-only security model (vs ATECC508A-MAHTN-T)
Design Notes
Configuration-zone fusing is irreversible. Before locking, verify the IO interface selection (I2C for the MAHDA variant), I2C address, zone read/write permissions, and slot key usage. A misconfigured lock either bricks the device for your intended protocol or weakens key protection. Prototype with unlocked configuration first, then fuse only after host firmware passes end-to-end authentication on the production PCB.
Keep the I2C traces from host SDA/SCL to the ATSHA204A under 20 cm where possible and include 2.2k to 4.7k pull-up resistors sized for your bus capacitance. Connect the exposed pad to ground for thermal and mechanical stability on the 2x3 mm UDFN. Provide a 100 nF ceramic decoupling capacitor within 2 mm of the VCC pin, and route the authenticator away from switching-regulator nodes to keep the analog front end of the die quiet during hash operations.
Estimated: at a typical active current of 0.5 mA on a 3.3 V rail, an authentication burst consumes about 1.65 mW and lasts only milliseconds; in battery-powered consumables the dominant energy term is leakage in sleep, so ensure the host actually releases the bus so the device can enter its sleep state between transactions. Do not hold SDA/SCL asserted low after the transaction, as that can prevent sleep and drain coin cells measurably faster.
The device input thresholds depend on the VCC level in sleep and idle modes per the ATSHA204A datasheet electrical characteristics. On mixed-voltage boards (for example a 5 V-tolerant host talking to a 3.3 V authenticator), verify that host I2C drivers stay within the datasheet VIH/VIL window at your supply, or add level translation. Margin here is the most common cause of intermittent authentication failures on prototype boards.
Compliance Information
RoHS compliant and lead-free per Microchip's standard CryptoAuthentication portfolio offering; REACH, halogen-free, and conflict-minerals declarations not captured in sourced listings - verify on Microchip's compliance page.
