MAX1840/W - SIM/Smart-Card Level Translator | Analog Devices
料号： MAX1840/W ✓ 量产中MAX1840/W 概述
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.
直接替换替代料： MAX1840/W ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
MAX1841EUB+
✅ 直接替换📋 参考替代料（不在目录中）
MAX1840EUB+
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
MAX1840/W 规格参数
| 功能 | SIM/smart-card level translator |
| Supply Voltage Range | 2.7 V to 5.5 V |
| 封装 | 10-pin µMAX (1.09 mm max height) |
| 安装类型 | Surface Mount |
| ESD Protection (card side) | ±10 kV Human Body Model |
| 工作温度范围 | -40 °C to +85 °C |
| GSM Compliance | GSM test specifications 11.11 and 11.12 |
| Supported Interfaces | SIM, smart card, SPI, QSPI, MICROWIRE |
| RoHS 状态 | Compliant (W = lead-free variant) |
| Lead-Free | Yes |
| 引脚数量 | 10 |
MAX1840/W 引脚配置
| 引脚 1 | VCC — Supply voltage input (2.7 V to 5.5 V) |
| 引脚 2 | GND — Ground |
| 引脚 3 | HOST_CLK — Host-side clock input |
| 引脚 4 | HOST_RST — Host-side reset input |
| 引脚 5 | HOST_DATA — Host-side bidirectional data |
| 引脚 6 | CARD_DATA — Card-side bidirectional data (ESD protected) |
| 引脚 7 | CARD_RST — Card-side reset output (ESD protected) |
| 引脚 8 | CARD_CLK — Card-side clock output (ESD protected) |
| 引脚 9 | CARD_VCC — Card-side supply / reference |
| 引脚 10 | NC — Not connected (per datasheet) |
典型应用
MAX1840/W 适用于 6 应用s: 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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推荐产品汇总
工程参考数据： MAX1840/W ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | 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 |
关键差异点
- Ultra-small 1.09 mm-high 10-pin µMAX package （对比 MAX1841EUB+)
- ±10 kV HBM ESD protection on card-side pins （对比 MAX1841EUB+)
- GSM 11.11/11.12 compliance （对比 MAX1841EUB+)
设计说明
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.
合规信息
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.
