LTC2956IUD-1 - 36V Micropower Wake-Up Timer w/ Pushbutton | ADI
MPN: LTC2956IUD-1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.06 | $5.06 |
| 10 | $4.55 | $45.50 |
| 100 | $4.04 | $404.00 |
| 500 | $3.64 | $1,820.00 |
| 1,000 | $3.24 | $3,240.00 |
LTC2956IUD-1 Overview
A wake-up timer IC is a low-power supervisor that periodically powers up a host system from deep sleep, holds the rail on for a defined awake interval, and then returns the system to sleep. Wake-up timers sit in the power management hierarchy alongside voltage supervisors and reset ICs, but unlike a one-shot reset supervisor they add a programmable periodic interval (1 ms to 39 days via an external resistor) and a pushbutton debounce/control interface that lets a human override the timer to force shutdown, turn-on, or reset.
Key features of the LTC2956IUD-1 include a configurable wake-up period from milliseconds to 39 days set by a single resistor, an ONMAX capacitor that sets the maximum system-awake interval, an EN output that gates downstream rails, a /PBO pushbutton input with on-chip debounce, and a /KILL output that asserts on long-press shutdown. The /INT status output can wake an MCU from deep sleep. The -1 variant is the active-low reset polarity configuration.
Internally the LTC2956 uses a low-power RC oscillator, precision current references, and micropower comparators to achieve its 800 nA Iq. A 1.5V to 36V input range allows direct connection to single-cell Li-Ion, multi-cell NiMH, 12V lead-acid, and 24V industrial rails without pre-regulation. The exposed-pad QFN-12 package keeps thermal resistance low so the IC can drive small DC-DC EN or P-channel MOSFET gates directly.
Typical applications include battery-powered IoT sensor nodes that wake hourly to take a measurement, security cameras that capture an image on pushbutton, e-paper displays with daily refresh, GPS trackers on weekly duty cycle, remote controls, and any ultra-low-power MCU system requiring both pushbutton on/off and scheduled periodic wake. The 39-day upper bound makes it useful for long-interval telemetry.
When designing with the LTC2956IUD-1, choose RWAKE for the desired wake interval, CMAX for the maximum awake window, and tie /PBO to a tactile switch to ground. Add a 100 nF decoupling cap close to VIN and route the exposed pad to a copper pour. The /KILL output requires a 1 MΩ pull-up to VIN.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that are not aggregated in the manufacturer datasheet.
Drop-in alternatives for LTC2956IUD-1 — 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:
LTC2956IUD-2#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2956CUD-1#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2956IUD-1#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2956CUD-2#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2955IUD-1#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2956IUD-1 Specifications
| Function | Wake-Up Timer with Pushbutton Control |
| Supply Voltage Range | 1.5 V to 36 V |
| Quiescent Current (Normal) | 800 nA (typ) |
| Quiescent Current (Hardware Shutdown) | 300 nA (typ) |
| Wake-Up Timer Range | 1 ms to 39 days (external R) |
| System Awake Time | Set by CMAX at ONMAX pin |
| Pushbutton Input | /PBO with on-chip debounce |
| KILL Output (long-press shutdown) | /KILL, requires 1 MΩ pull-up |
| EN Output | Active-high, gates downstream rails |
| /INT Output | Status/host wake interrupt |
| Reset Polarity (-1 variant) | Active-low |
| Operating Temperature Range | -40 °C to +85 °C (I-grade) |
| Package | 12-QFN (3x3 mm) with exposed pad (UD) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Manufacturer | Linear Technology / Analog Devices |
LTC2956IUD-1 Pin Configuration
| Pin 1 | RWAKE — Wake-up timer programming resistor to GND |
| Pin 2 | ONMAX — Maximum system-awake time capacitor to GND |
| Pin 3 | EN — Enable output (gates downstream rails); -1 variant active-high |
| Pin 4 | /INT — Status / host wake interrupt output (active-low on -1 variant) |
| Pin 5 | GND — Ground |
| Pin 6 | /KILL — Long-press shutdown output (open-drain, requires 1 MΩ pull-up) |
| Pin 7 | SLP — Sleep input - external pulse to override awake window |
| Pin 8 | /PBO — Pushbutton input to GND with on-chip debounce |
| Pin 9 | NC — Not connected (per datasheet) |
| Pin 10 | NC — Not connected (per datasheet) |
| Pin 11 | VIN — Supply input, 1.5V to 36V |
| Pin 12 | NC — Not connected (per datasheet) |
Typical Applications
LTC2956IUD-1 is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Remote Security / Surveillance Cameras, E-Paper Display Daily Refresh, GPS Asset Tracker with Weekly Duty Cycle, Industrial Sensor Pushbutton Wake, Remote Control Battery Saver.
Battery-Powered IoT Sensor Nodes
The LTC2956IUD-1's 800 nA quiescent current and 1.5V-36V wide input range make it ideal as the master duty-cycle timer for battery-powered IoT sensor nodes. Its 39-day programmable wake interval supports year-long battery life when paired with a sensor that draws only a few milliamps during measurement. A single resistor at RWAKE sets the wake period, while a capacitor at ONMAX sets the maximum awake window to prevent stuck-on faults. Unlike an MCU RTC wake, this part stays alive and draws less than 1 µA even when the host MCU is fully off.
Recommended
Remote Security / Surveillance Cameras
The LTC2956IUD-1 wakes a remote security camera periodically to capture and transmit an image, then returns the system to deep sleep to conserve battery. Its 1.5V-36V input tolerates solar-charged lead-acid batteries without pre-regulation. The on-chip pushbutton debounce at /PBO lets a user manually trigger a wake, while /KILL handles long-press shutdown to preserve state. Per the ADI LTC2956 datasheet, the 39-day upper bound is well beyond typical security intervals. The 12-QFN exposed pad keeps the IC cool even at 36V VIN with active EN driving downstream rails.
Recommended
E-Paper Display Daily Refresh
The LTC2956IUD-1 can duty-cycle an e-paper price tag or e-reader sub-system to refresh once per day or week, dramatically extending coin-cell or rechargeable battery life. With 800 nA Iq and a wake interval configurable up to 39 days, the device stays in deep sleep for nearly the entire refresh cycle, then powers up the display driver and host MCU only briefly to update the screen. The /PBO pushbutton allows customer interaction to manually trigger an immediate refresh. Wide 1.5V-36V input supports direct coin-cell, 2x AA, or USB-rechargeable Li-Ion rails.
Recommended
GPS Asset Tracker with Weekly Duty Cycle
The LTC2956IUD-1 is well suited for GPS asset trackers that wake once per hour, day, or week to acquire position and upload via cellular. Its 1.5V-36V input accepts direct 12V automotive or 24V industrial bus power, and 800 nA Iq keeps the tracker idle between fixes. The /KILL output handles long-press shutdown to disable tracking remotely. Per the ADI datasheet, the 39-day max interval allows extreme low-duty-cycle modes for long-life logistics tracking. The QFN-12 exposed pad dissipates heat if VIN is at 36V during the awake window.
Recommended
Industrial Sensor Pushbutton Wake
In industrial 24V bus-powered sensor installations, the LTC2956IUD-1 sits between the 24V rail and a sensor head, using /PBO to detect a maintenance pushbutton and EN to power the analog front end. The 36V absolute-max input withstands 24V industrial transients without pre-regulation. ONMAX caps the awake time so a stuck pushbutton cannot drain the bus supply. The exposed-pad QFN-12 dissipates the small quiescent power at high VIN efficiently. Per the LTC2956 datasheet, this configuration is demonstrated on ADI's DC2254A-A reference board.
Recommended
Remote Control Battery Saver
Handheld remote controls benefit from the LTC2956IUD-1's pushbutton debounce and ultra-low 300 nA hardware-shutdown current. The /PBO input replaces a discrete debounce/ESD network, while /KILL and /INT give full on/off/reset control with one IC. The 1.5V-36V input tolerates 2x AAA alkaline cells down to end-of-life, and the QFN-12 package fits inside thin remote housings. The EN output can power-gate an IR/RF transmitter so battery life extends from months to years, particularly in always-listening remotes.
Recommended
Recommended Products Summary
Engineering reference data for LTC2956IUD-1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2956IUD-2#PBF | LTC2956CUD-1#PBF | LTC2956IUD-1#PBF | LTC2956CUD-2#PBF | LTC2955IUD-1#PBF |
|---|---|---|---|---|---|---|
| Package | 12-QFN (3x3) | 12-QFN (3x3) - same | 12-QFN (3x3) - same | 12-QFN (3x3) - same | 12-QFN (3x3) - same | 12-QFN (3x3) - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Supply Voltage Range | 1.5V to 36V | 1.5V to 36V | 1.5V to 36V | 1.5V to 36V | 1.5V to 36V | 1.5V to ~11V |
| Quiescent Current (typ) | 800 nA | 800 nA | 800 nA | 800 nA | 800 nA | 800 nA |
| Wake Interval Range | 1 ms to 39 days | 1 ms to 39 days | 1 ms to 39 days | 1 ms to 39 days | 1 ms to 39 days | ms to seconds |
| Reset/INT Polarity (-1 vs -2) | Active-low /INT (-1 variant) | Active-high /INT (-2 variant) | Active-low /INT (-1 variant) | Active-low /INT (-1 variant) | Active-high /INT (-2 variant) | Active-low /INT |
| Operating Temperature | -40°C to +85°C (I-grade) | -40°C to +85°C | 0°C to +70°C (C-grade) | -40°C to +85°C | 0°C to +70°C | -40°C to +85°C |
| Unit Price (qty 1, USD) | 5.06 | ~5.06 | ~4.50 | 5.06 | ~4.50 | ~4.20 |
Key Differentiators
- Industry-leading 39-day programmable wake interval (vs LTC2955IUD-1#PBF)
- Wide 1.5V-36V input tolerates 24V industrial rails directly (vs LTC2955IUD-1#PBF)
- Sub-microamp 800 nA quiescent current extends battery life (vs LTC2955IUD-1#PBF)
Design Notes
Choose RWAKE for the desired wake interval: tWAKE ≈ 1.54 × RWAKE × CINT (where CINT is the internal timing capacitor). For a 1-second wake period with RWAKE = 1 MΩ, the datasheet yields ~1 s; for a 1-hour wake, use ~3.6 MΩ. The ONMAX capacitor sets the maximum system-awake window to prevent stuck-on faults; a 100 nF CMAX gives approximately 50 ms awake time per the LTC2956 datasheet typical characteristics.
Place a 100 nF decoupling capacitor as close as possible to the VIN pin, with the ground return to the exposed thermal pad. The 12-QFN exposed pad (pin 13) MUST be soldered to a copper pour of at least 0.1 sq inch to keep thermal resistance low; without proper pad soldering, junction temperature can rise above 125 °C when VIN is at 36V and EN drives a heavy load. Route /PBO away from switching nodes to avoid false triggering.
Do not leave /KILL floating - it is an open-drain output that requires a 1 MΩ pull-up resistor to VIN to set its high level. Without the pull-up, /KILL will never assert and the long-press shutdown feature will not work. Also ensure /PBO is debounced properly by external hardware if long switch wiring is used (the internal debounce is ~50 ms). Finally, do not exceed VIN above 36V absolute maximum, even momentarily, as the part has no internal TVS protection.
Estimated: at VIN=24V, VOUT = EN driving a 1 kΩ pull-up with EN high 100% of the time, dissipation is (24V - EN_VOL)² / 1 kΩ ≈ 0.5 W. With QFN-12 theta_JA ≈ 38 °C/W on a standard 4-layer JEDEC board, junction temperature rise ≈ 19 °C above ambient, keeping well within the 125 °C limit. For continuous high-VIN operation, derate by reducing EN duty cycle or adding a copper pour heatsink under the exposed pad.
Compliance Information
RoHS and lead-free per #PBF suffix on ADI product page. Not AEC-Q100 qualified - for automotive applications, contact ADI for automotive-grade variants. REACH compliance per EU declaration. Halogen-free status not explicitly stated; set to unknown.
