Part A
MAX6804US29D3+T
類比設備股份有限公司/Maxim集成
- Lifecycle
- Active
- Stock
- 857 件
- Package
- SOT-143-4
- Series
- PMIC-首長
Replacement verdict
Not a drop-in replacement
The MAX6804US29D3+T and MAX6865UK46D2S+T are not drop-in replacements for each other. Although both are single-channel microprocessor supervisory circuits in SOT-23 packages, they differ fundamentally in reset threshold voltage, reset output type, reset timeout period, and manual reset functionality, making direct substitution impractical without circuit redesign.
Different reset threshold
Different output type
Different reset timeout
Different manual reset
Parts at a glance
Part B
MAX6865UK46D2S+T
類比設備股份有限公司/Maxim集成
- Lifecycle
- Active
- Stock
- 6142 件
- Package
- SOT-753
- Series
- PMIC-首長
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | MAX6804US29D3+T | MAX6865UK46D2S+T | Why it matters |
|---|---|---|---|
| Reset Threshold Voltage | 2.93 V | 4.63 V | Determines the supply voltage level at which the supervisor asserts a reset, so the two parts monitor different nominal rails. |
| Reset Output Type | Push-pull, active-low | Open-drain, active-low | Push-pull drives the line both ways without a pull-up, while open-drain requires an external pull-up resistor, affecting board design. |
| Reset Timeout Period | 3 ms (min) | 120 ms (min) | Sets how long reset stays asserted after the supply recovers, which must match the processor's required power-on reset duration. |
| Manual Reset Input | Yes | No | A manual reset pin allows an external pushbutton or logic signal to force a reset, a feature present in only one of the two devices. |
| Watchdog Timer | No | Yes | A watchdog monitors processor activity and resets it if it hangs, so only one part provides this supervisory function. |
| Package / Pin Count | SOT-143, 4 pins | SOT-23-5, 5 pins | Different footprints and pin counts prevent direct drop-in replacement without a PCB layout change. |
| Supply Voltage Range | 1.0 V to 5.5 V | 1.2 V to 5.5 V | Defines the operating window over which the supervisor functions correctly, affecting compatibility with low-voltage rails. |
| Supply Current | 3.5 µA (typ) | 7 µA (typ) | Quiescent current impacts battery life in portable designs, so the lower-current part is preferable for power-sensitive applications. |
| Reset Output Configuration Count | Single reset output | Single reset output | Both provide one reset output, so the number of monitored signals is equivalent between the two devices. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | MAX6804US29D3+T | MAX6865UK46D2S+T |
|---|---|---|
| Part Status | Active | Obsolete |
| Type | Simple Reset/Power-On Reset | Simple Reset/Power-On Reset |
| Number of Voltages Monitored | 1 | 1 |
| Voltage - Threshold | 2.93V | 4.625V |
| Output | Push-Pull, Totem Pole | Push-Pull, Totem Pole |
| Reset | Active Low | Active Low |
| Reset Timeout | 100ms Minimum | 40ms Minimum |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary differences between the MAX6804US29D3+T and the MAX6865UK46D2S+T?
The MAX6804US29D3+T is a microprocessor supervisory circuit with a 2.93V reset threshold and a 150ms minimum reset timeout period, housed in a 4-pin SOT-143 package. The MAX6865UK46D2S+T is a microprocessor supervisory circuit with a 4.63V reset threshold and a 120ms minimum reset timeout period, housed in a 5-pin SOT-23 package. They differ in reset threshold voltage, reset timeout period, and package pin count.
Are the MAX6804US29D3+T and MAX6865UK46D2S+T pin-to-pin compatible?
No. The MAX6804US29D3+T uses a 4-pin SOT-143 package, while the MAX6865UK46D2S+T uses a 5-pin SOT-23 package. The pin counts and package footprints differ, so they are not direct pin-to-pin replacements.
What is the reset threshold voltage for each device?
The MAX6804US29D3+T has a reset threshold voltage of 2.93V. The MAX6865UK46D2S+T has a reset threshold voltage of 4.63V. These thresholds determine the supply voltage level at which the reset output is asserted.
What is the minimum reset timeout period for each device?
The MAX6804US29D3+T provides a minimum reset timeout period of 150ms. The MAX6865UK46D2S+T provides a minimum reset timeout period of 120ms. The timeout period is the time the reset output remains asserted after the supply voltage rises above the reset threshold.
Can the MAX6804US29D3+T and MAX6865UK46D2S+T be used interchangeably in the same design?
No. Due to differences in reset threshold voltage (2.93V vs. 4.63V), reset timeout period (150ms vs. 120ms), and package type (4-pin SOT-143 vs. 5-pin SOT-23), they are not interchangeable without redesigning the circuit and PCB layout to accommodate these differences.
What supply voltage ranges are suitable for each device?
The MAX6804US29D3+T is designed for monitoring supply voltages around its 2.93V reset threshold, typically used in 3V or 3.3V systems. The MAX6865UK46D2S+T is designed for monitoring supply voltages around its 4.63V reset threshold, typically used in 5V systems. Exact operating supply voltage ranges should be verified from the respective manufacturer datasheets.
Do both devices provide a manual reset input?
No. The MAX6804US29D3+T does not include a manual reset input. The MAX6865UK46D2S+T includes a manual reset input, which allows the reset output to be asserted by an external pushbutton or logic signal. This is a functional difference that affects system design.
What output types do these supervisory circuits provide?
The MAX6804US29D3+T provides an active-low push-pull reset output. The MAX6865UK46D2S+T provides an active-low open-drain reset output. The output type affects how the reset signal interfaces with the monitored processor and whether an external pull-up resistor is required.