MAX1840/W - SIM/Smart-Card Level Translator | Analog Devices
Référence : MAX1840/W ✓ ActifMAX1840/W Présentation
A level translator (also called a level shifter) is a mixed-signal interface IC that converts logic signals between two different voltage domains. Within the semiconductor hierarchy, the MAX1840/W sits under interface ICs, which belong to the broader analog/mixed-signal integrated circuit family. SIM and smart-card interfaces require a dedicated translator because the card operates at 1.8 V, 3 V, or 5 V while the host controller may run at a different rail; the translator must also survive the ESD events that occur when a card is inserted or removed.
The MAX1840/W integrates level-shifting circuitry for the SIM clock, reset, and bidirectional data lines, plus ESD protection diodes rated to ±10 kV (Human Body Model) on the card-side pins. Its ultra-small 10-pin µMAX package occupies roughly half the board area of an 8-pin SOIC, which is critical in GSM handsets where PCB real estate is at a premium. The device is specified over the -40 °C to +85 °C extended temperature range.
Typical applications include SIM interfaces in GSM cellular telephones, smart-card readers, and SPI/QSPI/MICROWIRE level translation where a compact, ESD-hardened interface is needed. The MAX1840/W is the lead-free (W) variant of the MAX1840 family, making it suitable for RoHS-compliant production.
When designing with the MAX1840/W, place the ESD protection close to the card connector and keep the card-side traces short to preserve the ±10 kV rating. The device is a legacy Maxim part now manufactured by Analog Devices; verify lifecycle status and availability before committing to new designs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Alternatives de remplacement direct pour MAX1840/W — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
MAX1841EUB+
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
MAX1840EUB+
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
MAX1840/W Spécifications
| Fonction | SIM/smart-card level translator |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Boîtier | 10-pin µMAX (1.09 mm max height) |
| Type de montage | Surface Mount |
| ESD Protection (card side) | ±10 kV Human Body Model |
| Plage de température de fonctionnement | -40 °C to +85 °C |
| GSM Compliance | GSM test specifications 11.11 and 11.12 |
| Supported Interfaces | SIM, smart card, SPI, QSPI, MICROWIRE |
| Statut RoHS | Compliant (W = lead-free variant) |
| Lead-Free | Yes |
| Nombre de broches | 10 |
Configuration des broches de MAX1840/W
| Broche 1 | VCC — Supply voltage input (2.7 V to 5.5 V) |
| Broche 2 | GND — Ground |
| Broche 3 | HOST_CLK — Host-side clock input |
| Broche 4 | HOST_RST — Host-side reset input |
| Broche 5 | HOST_DATA — Host-side bidirectional data |
| Broche 6 | CARD_DATA — Card-side bidirectional data (ESD protected) |
| Broche 7 | CARD_RST — Card-side reset output (ESD protected) |
| Broche 8 | CARD_CLK — Card-side clock output (ESD protected) |
| Broche 9 | CARD_VCC — Card-side supply / reference |
| Broche 10 | NC — Not connected (per datasheet) |
Applications typiques
MAX1840/W convient pour 6 applications: GSM Cellular Telephone SIM Interface, Smart Card Readers, SPI/QSPI/MICROWIRE Level Translation, Portable Consumer Devices with Card Slots, Industrial Smart-Card Terminals, Legacy Design Maintenance and Repair.
GSM Cellular Telephone SIM Interface
The MAX1840/W is designed specifically for the SIM interface in GSM cellular telephones, where it shifts logic levels between the baseband controller and the 1.8 V/3 V/5 V SIM card while providing ±10 kV HBM ESD protection at the card connector. Its 10-pin µMAX package at 1.09 mm height fits the tight vertical space of handset PCB stacks, and its GSM 11.11/11.12 compliance ensures interoperability with network test requirements. Placed between the baseband SIM controller and the SIM socket, the device adds no significant series resistance to the clock and data lines, preserving signal integrity at the SIM clock rates used in GSM handsets.
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Smart Card Readers
Smart-card readers require a robust level translator between the reader controller and the card contacts, and the MAX1840/W provides exactly this function with ±10 kV ESD protection on the card side. The 2.7 V to 5.5 V supply range lets the reader run from a 3.3 V or 5 V rail, while the 10-pin µMAX package keeps the reader PCB compact. In a reader design, the MAX1840/W sits directly behind the card connector, so its ESD diodes absorb discharge events from user card insertion; keep the card-side traces short and route them away from noisy switching supplies to preserve the full ESD rating.
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SPI/QSPI/MICROWIRE Level Translation
The MAX1840/W supports SPI, QSPI, and MICROWIRE level translation, making it useful wherever a serial peripheral runs at a different logic level from its host controller. Its bidirectional level-shifting architecture handles the data lines while the clock and chip-select paths are translated in the same package, and the 2.7 V to 5.5 V range covers both 3.3 V and 5 V systems. Because the device is optimized for SIM/smart-card timing rather than high-speed SPI, verify the maximum data rate against the datasheet before using it in fast serial buses; for low-to-moderate SPI clock rates it provides a compact single-package solution.
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Portable Consumer Devices with Card Slots
Portable consumer devices such as cameras, media players, and handheld terminals with memory-card or smart-card slots benefit from the MAX1840/W's combination of level shifting and ESD protection in a 1.09 mm-high package. The device's low profile allows it to be placed on the same side of the PCB as the card connector without interfering with the enclosure, and its ±10 kV HBM rating protects the host ASIC from user-induced discharge. Designers should add a small bypass capacitor on the supply pin close to the device and keep the card-side ESD path short to maintain protection effectiveness in the final product.
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Industrial Smart-Card Terminals
Industrial smart-card terminals used in access control, identification, and payment systems need reliable level translation over the -40 °C to +85 °C extended temperature range that the MAX1840/W supports. The device's GSM 11.11/11.12 compliance provides a proven interoperability baseline, and its ±10 kV ESD protection guards the terminal controller against discharge from frequent card use in the field. In industrial enclosures, place the MAX1840/W close to the card connector and provide a clean 3.3 V or 5 V supply; the 10-pin µMAX package simplifies layout in the dense control boards typical of these terminals.
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Legacy Design Maintenance and Repair
Because the MAX1840/W is a legacy Maxim part now produced by Analog Devices, a major application is maintaining and repairing existing GSM handset and smart-card reader designs that already use it. Repair depots and sustaining engineering teams need the exact part to avoid re-qualifying a board, and the MAX1840/W's continued availability through distributors such as DigiKey and Rochester Electronics supports this. When sourcing for repair, verify the W (lead-free) suffix matches the original build to avoid mixing leaded and lead-free assembly processes, and confirm date-code authenticity through authorized channels.
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Récapitulatif des produits recommandés
Données de référence d'ingénierie pour MAX1840/W — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | MAX1841EUB+ | MAX1840EUB+ |
|---|---|---|---|
| Package | 10-pin µMAX | 10-pin µMAX - same | 10-pin µMAX - same |
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Function | SIM/smart-card level translator | SIM/smart-card level translator | SIM/smart-card level translator |
| GSM Compliance | GSM 11.11 and 11.12 | GSM 11.11 and 11.12 | GSM 11.11 and 11.12 |
| Lead-Free (W suffix) | Yes | Yes (+ suffix) | Yes (+ suffix) |
| Level-Shifting Configuration | MAX1840 configuration | MAX1841 configuration - differs, verify pinout | MAX1840 configuration - identical |
Principaux différenciateurs
- Ultra-small 1.09 mm-high 10-pin µMAX package (vs MAX1841EUB+)
- ±10 kV HBM ESD protection on card-side pins (vs MAX1841EUB+)
- GSM 11.11/11.12 compliance (vs MAX1841EUB+)
Notes de conception
Place the MAX1840/W as close as possible to the SIM or smart-card connector so the card-side ESD-protected traces stay short. The ±10 kV HBM rating applies at the device pins; long traces between the connector and the IC add inductance and resistance that reduce the effective protection at the connector. Route card-side traces away from switching regulators and RF power amplifiers to avoid coupling noise into the SIM clock and data lines.
Decouple the VCC pin with a 0.1 µF ceramic capacitor placed within a few millimeters of the device, and add a 1 µF bulk capacitor nearby if the supply rail is shared with switching circuitry. The MAX1840/W operates from 2.7 V to 5.5 V, so confirm the host rail stays within this window under all load conditions; a supply below 2.7 V may cause the level translator to output invalid card-side levels.
Do not assume the MAX1841 is a pin-identical substitute for the MAX1840/W. Both are 10-pin µMAX SIM/smart-card translators, but the Analog Devices datasheet presents them in a product selection table with different level-shifting configurations. Verify the pinout and host/card rail arrangement against the datasheet before substituting, and confirm the W (lead-free) suffix matches your assembly process to avoid mixing leaded and lead-free reflow profiles.
Informations de conformité
The W suffix denotes the lead-free variant; RoHS compliance is indicated by the lead-free designation. REACH, halogen-free, and conflict-minerals status are not stated in the verified data.
