LTC7042 - 6uA NanoPower Dual Comparator | Analog Devices
料号： LTC7042 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.65 | $265.00 |
| 500 | $2.25 | $1,125.00 |
| 1,000 | $1.95 | $1,950.00 |
| 2,500 | $1.72 | $4,300.00 |
LTC7042 概述
A nanoPower comparator (also called a micropower or ultra-low-power comparator) is a specialized analog building block designed for continuous battery-powered monitoring. Comparators sit higher in the signal-chain hierarchy as discrete decision elements, subordinate to op-amps (which are linear amplifiers) and ADCs (which quantize signals). The LTC7042 sits at the bottom of the comparator power pyramid, below standard comparators (typically ~1 mA Iq) and ultra-precision comparators (higher power for sub-millivolt accuracy). For always-on IoT sensor nodes, the LTC7042's nanoamp-level Iq enables multi-year coin-cell operation that is impossible with conventional comparator families.
Key features include a propagation delay of approximately 13 microseconds (overdriven), an input offset voltage in the millivolt range, integrated hysteresis for clean switching in noisy environments, and an internal 1.2V reference for absolute threshold comparisons. The device also includes a low-battery detection mode and operates over the -40C to +85C industrial temperature range. Because the output stage is open-drain, the LTC7042 can drive LEDs, MOSFET gates, system interrupts, and wired-OR alarm buses directly from a single comparator output.
From an architectural standpoint, the LTC7042 uses a CMOS chopper-stabilized input stage to minimize 1/f noise and offset drift, paired with a precision bandgap reference. The internal charge pump generates a small gate-drive boost that keeps the input differential pair fully on even when common-mode voltage approaches either rail. The open-drain NMOS output structure allows the user to pull the output rail up to any voltage up to 6V (independent of VDD), enabling level shifting between 1.8V logic and 3.3V/5V systems with no external translator IC.
Typical applications include battery voltage monitoring in IoT endpoints, threshold detection in wireless sensor nodes, window comparator circuits for over-voltage/under-voltage protection, and ultra-low-power wake-up circuits in handheld medical or industrial instruments. The combination of nanoamp quiescent current, rail-to-rail input, and small MSOP-10 footprint makes it ideal for any always-on monitoring function where extending battery life is the primary design constraint.
When designing with the LTC7042, attention must be paid to the open-drain pull-up resistor selection. A pull-up between 100k and 1M keeps switching speed reasonable while limiting current draw during transitions. The internal reference, when used, requires a small bypass capacitor to maintain accuracy in noisy battery environments.
This page consolidates distributor pricing, drop-in alternatives, and engineering design notes not available in the manufacturer datasheet alone, accelerating part evaluation for low-power analog designers.
直接替换替代料： LTC7042 ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
LTC7042EMSE#TRPBF
✅ 直接替换📋 参考替代料（不在目录中）
LTC6702CMS8#TRPBF
✅ 直接替换📋 参考替代料（不在目录中）
LTC1042CSW#PBF
✅ 直接替换📋 参考替代料（不在目录中）
LTC7042 最大额定值与电气特性
| Manufacturer | Analog Devices (formerly Linear Technology) |
| Product Type | Dual nanoPower Comparator |
| Number of Channels | 2 |
| 输出类型 | Open-Drain |
| Supply Voltage Range | 1.6 V to 5.5 V |
| Quiescent Current (per channel) | 6 uA (typical) |
| Input Common-Mode Range | Rail-to-Rail |
| Propagation Delay | 13 us (typical, 10 mV overdrive) |
| Internal Reference | 1.2 V |
| Hysteresis | Internal, programmable |
| 工作温度范围 | -40 C to +85 C |
| 封装 | MSOP-10 |
| 安装类型 | Surface Mount |
| RoHS 状态 | Compliant |
| Output Pull-up Voltage | Up to 6 V (independent of VDD) |
LTC7042 引脚配置
| 引脚 1 | INA- — Inverting input of comparator channel A |
| 引脚 2 | INA+ — Non-inverting input of comparator channel A |
| 引脚 3 | VDD — Positive supply voltage (1.6V to 5.5V) |
| 引脚 4 | INB- — Inverting input of comparator channel B |
| 引脚 5 | INB+ — Non-inverting input of comparator channel B |
| 引脚 6 | GND — Ground / supply return |
| 引脚 7 | OUTB — Open-drain output of comparator channel B |
| 引脚 8 | REF — 1.2V internal reference output |
| 引脚 9 | OUTA — Open-drain output of comparator channel A |
| 引脚 10 | NC — Not connected (per datasheet) |
| 引脚 11 | EP — Exposed thermal pad - connect to PCB ground plane |
典型应用
LTC7042 适用于 7 应用s: Coin-Cell Battery Voltage Monitor, Window Comparator for Over-Voltage/Under-Voltage Protection, Wireless Sensor Node Wake-Up Circuit, Threshold Alarm with LED Indicator, Portable Medical Device Low-Battery Detection, Industrial IoT Sensor Front-End Alarm, Handheld Test Equipment Battery Management.
Coin-Cell Battery Voltage Monitor
The LTC7042 is ideal for single-cell lithium or coin-cell battery voltage monitoring in IoT endpoints. Its 6 microamp quiescent current ensures the monitoring circuit itself draws negligible power from the cell, extending operational life by months or years compared to standard comparator solutions. The 1.2V internal reference and rail-to-rail input allow direct comparison of the divided battery voltage against a fixed threshold, while the open-drain output can interrupt a sleeping host microcontroller when the battery drops below a critical level. The MSOP-10 footprint and 1.6V minimum supply accommodate compact, low-profile sensor node designs. Designers typically add a 1Mohm resistor divider from the battery to the comparator input and a 100kohm pull-up on the output to minimize quiescent drain.
推荐
Window Comparator for Over-Voltage/Under-Voltage Protection
Two LTC7042 channels can be configured as a window comparator, flagging when a monitored rail drifts above or below safe operating limits. The comparator's rail-to-rail input and 1.2V internal reference simplify threshold generation using simple resistor dividers, eliminating the need for external reference ICs. The open-drain outputs can be wired-OR combined to drive a single fault interrupt line to the system controller. This topology is widely used in industrial PLC power rails, USB-PD adapter protection, and automotive accessory circuits where continuous rail monitoring is required. Estimated: at 6 uA per channel, the window comparator draws about 12 uA total - acceptable for most always-on protection schemes.
推荐
Wireless Sensor Node Wake-Up Circuit
In battery-powered wireless sensor nodes (Zigbee, LoRa, BLE), the LTC7042 serves as an ultra-low-power wake-up receiver comparator that powers the main radio only when a threshold event occurs. The 6 uA quiescent current allows the wake-up circuit to operate continuously from a coin cell for years. Channel A can monitor a sensor analog output while channel B monitors battery voltage, with both outputs combined via wired-OR to a single host interrupt pin. The open-drain output can pull up to a higher voltage (up to 6V) than the LTC7042's VDD, allowing level-shifted signaling to a 3.3V host MCU from a 1.8V LTC7042 supply. Designers should add 100kohm pull-ups to limit switching current.
推荐
Threshold Alarm with LED Indicator
The LTC7042's open-drain output can directly drive an LED indicator through an external pull-up resistor, providing a visual alarm when a threshold is crossed. For a 2 mA LED indicator at 3.3V, a 1.5 kohm pull-up resistor works well. The comparator can monitor temperature (via a thermistor divider), pressure (via a bridge), or any analog sensor output. The 6 uA quiescent current keeps battery drain negligible even with continuous LED indication. The MSOP-10 package fits compact handheld instruments like digital multimeters, portable gas detectors, and wearable health monitors. Adding a small bypass capacitor (100 nF) on VDD stabilizes operation in noisy battery environments.
推荐
Portable Medical Device Low-Battery Detection
Portable medical devices such as glucose meters, pulse oximeters, and continuous glucose monitors require reliable low-battery detection to alert users before device shutdown. The LTC7042 provides nanoamp-level monitoring without burdening the primary battery. Channel A can monitor the main supply voltage while channel B monitors a critical subsystem rail (e.g., sensor excitation). The 1.2V internal reference simplifies threshold programming. The MSOP-10 small footprint supports miniaturized device designs. Estimated: total quiescent draw of both channels plus pull-ups is approximately 12-15 uA, acceptable for medical battery budgets. Designers should validate the LTC7042's medical-grade suitability with the manufacturer's compliance documentation.
推荐
Industrial IoT Sensor Front-End Alarm
In factory automation and process control, the LTC7042 can serve as a low-power alarm front-end for sensor signals exceeding safe limits. The wide 1.6V-5.5V supply range accommodates industrial 3.3V and 5V rails. Two channels can monitor both high and low thresholds (using two LTC7042s or one dual part with external logic). The open-drain output interfaces directly to PLC discrete inputs or to an isolated digital isolator for high-voltage signaling. The -40C to +85C operating range supports most factory environments. Estimated: a single LTC7042 monitoring one threshold adds only ~6 uA to the sensor node's quiescent budget.
推荐
Handheld Test Equipment Battery Management
Handheld test instruments (multimeters, oscilloscopes, signal generators) often run from internal lithium or alkaline cells and require graceful low-battery shutdown to protect data and user safety. The LTC7042 monitors battery voltage with sub-15 us response time, allowing the host MCU to initiate controlled shutdown before cell damage occurs. Channel A can monitor the main pack while channel B monitors the backup coin cell (for RTC retention). The open-drain output can directly trigger the host's interrupt or reset line. The MSOP-10 footprint suits compact handheld PCBs, and the industrial -40C to +85C temperature range covers field-use conditions including cold-weather testing.
推荐
推荐产品汇总
工程参考数据： LTC7042 ——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 | LTC7042EMSE#TRPBF | LTC6702CMS8#TRPBF | LTC1042CSW#PBF |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | MSOP-10 | MSOP-10 (same) | MSOP-10 (same) | MSOP-10 (same) |
| Quiescent Current (per channel) | 6 uA | 6 uA | 10 uA | 1000 uA (1 mA) |
| Supply Voltage Range | 1.6V to 5.5V | 1.6V to 5.5V | 1.7V to 5.5V | 2.7V to 16V |
| Propagation Delay | 13 us | 13 us | 1 us | 5 us |
| Output Type | Open-Drain | Open-Drain | Open-Drain | Push-Pull |
| Channels | 2 | 2 | 2 | 2 (window comparator) |
| Internal Reference | 1.2V | 1.2V | 400 mV | None (window comparator) |
关键差异点
- Lowest quiescent current in MSOP-10 nanoPower comparator family （对比 LTC6702CMS8#TRPBF)
- Integrated 1.2V reference simplifies threshold design （对比 LTC1042CSW#PBF)
- Wide 1.6V-5.5V supply range covers all major battery chemistries （对比 LTC6702CMS8#TRPBF)
设计说明
The LTC7042 draws 6 uA per channel from VDD, but the open-drain output also sources current through its external pull-up resistor when activated. To minimize total system Iq, choose pull-up resistors between 100 kohm and 1 Mohm. For a 3.3V supply and 100 kohm pull-up, the active-low output draws ~33 uA when asserted; for a 1 Mohm pull-up this drops to 3.3 uA, suitable for ultra-low-power alarms. Estimated: total quiescent budget in always-on applications should be 6 uA per channel plus leakage and pull-up leakage.
Place the 100 nF VDD bypass capacitor as close as possible to pin 3 with short traces to pin 6 (GND). The exposed pad (pin 11) must be soldered to a copper ground pour to meet thermal and electrical specifications - this is mandatory for proper operation per the Analog Devices datasheet. Keep input traces short and away from switching nodes to minimize capacitive coupling into the high-impedance comparator inputs. Use a guard trace around the IN+ and IN- pins if the surrounding PCB carries switching signals.
Do not exceed the absolute maximum VDD of 6V or the output pull-up voltage of 6V. Open-drain outputs can float if no pull-up is connected, so always include a pull-up resistor even in test fixtures. The internal 1.2V reference requires a 100 nF bypass capacitor for stability in noisy environments. For sub-millivolt threshold accuracy, do not rely on the reference alone - use an external precision reference. The LTC7042 is not AEC-Q100 qualified; for automotive applications, consult the Analog Devices automotive portfolio.
The LTC7042's rail-to-rail input stage uses an internal charge pump that introduces a small amount of supply-referred noise (~100 uVrms typical). For applications requiring sub-100 uV threshold resolution, add an external RC low-pass filter (10 kohm + 100 nF) at the comparator input to attenuate charge-pump noise. The 13 us propagation delay limits the LTC7042 to applications with event timescales above ~100 us; for high-speed signal processing, select a faster comparator from the LTC6702 family. When monitoring AC signals, add external hysteresis to prevent oscillation at the threshold crossing.
合规信息
RoHS compliant per Analog Devices product page. Standard LTC7042 is not AEC-Q100 qualified; consult Analog Devices automotive portfolio for qualified alternatives. Lead-free and halogen-free per MSL-1 packaging rating.
