The DS1233 from Dallas Semiconductor (now Analog Devices via Maxim) is the 5 V single-chip EconoReset; the "-5" grade is its tight 5%-tolerance option. DS1233Z-5+T&R is the SOT-223 surface-mount package on tape and reel. Like the rest of the family it folds the reference, comparator and reset timer into one three-terminal part, but the "-5" is chosen where the reset point must track a 5 V rail closely.

The function is the 5 V power-on and brownout reset, set to a 4.62 V trip (4.50 V min / 4.74 V max). Because the 5% window sits higher and tighter than the 10% grade's 4.375 V, the processor is held in reset until the 5 V rail is very close to nominal - useful for parts whose minimum operating voltage leaves little margin. The active-low /RST stays asserted below the trip and for a further 350 ms (250 ms to 450 ms) after VCC returns, then releases. The output is open-drain with an internal 5 kΩ pull-up.

As with every EconoReset, the DS1233 also debounces a reset pushbutton tied to its reset node, re-timing the 350 ms pulse so a manual press is clean. The reference is temperature-compensated from -40 to +85 °C at under 50 µA, and the basic reset needs no external components. The same die is available in a through-hole TO-92.

Note: Values are taken from the Dallas/Maxim DS1233 datasheet. The "-5" grade is the 5 V / 4.62 V (5%) version; confirm every parameter against the latest official documentation before committing a design.

DS1233Z-5+T&R is supplied in the surface-mount SOT-223 (the "Z" denotes the SOT-223; the tab and lead 4 are GND); "+" marks the RoHS-compliant lead-free finish and "T&R" the tape-and-reel packing. The same DS1233 die is also offered in a through-hole TO-92. Place the device near the processor reset pin, route /RST to the reset input, and add the optional 100 pF-0.01 µF debounce cap from the reset node to GND when a pushbutton is used. Package dimensions and pin-1 orientation are shown below.

📄 Full specifications are detailed in the official Dallas/Maxim DS1233 datasheet.

The SOT-223 brings out the supply, reset and ground:

• Pin 1 - GND: Ground (the large tab).
• Pin 2 - /RST: Reset output, active low, open drain (internal 5 kΩ pull-up).
• Pin 3 - VCC: +5 V supply (monitored against the 4.62 V trip).
• Pin 4 - GND: Ground (SOT-223 lead, common with the tab).

Refer to the package drawing below for the physical pin numbering of the SOT-223.

The parts below are related Dallas/Maxim reset and supervisory ICs in our catalog. They are not all drop-in replacements; verify the trip voltage, output type and pinout before substituting.

Selection Tips: Use the DS1233-5 (4.62 V, 5%) when a 5 V rail needs a tight, higher reset threshold; the DS1233-10 (4.375 V, 10%) gives a wider window, and the DS1233A covers 3.3 V. The DS1233D swaps to a push-pull output. For the smallest footprint the 3-pin MAX809 in SOT-23 is an alternative with a similar 4.63 V trip.

Dallas Semiconductor, now part of Analog Devices through Maxim Integrated, introduced the EconoReset line that turned the microprocessor power-on reset into a single low-cost chip. The DS1233 5 V part is offered in 5% and 10% trip grades; the "-5" suits designs that need the tighter, higher threshold.

The device is backed by full datasheet characterization and application notes on trip grades, pushbutton wiring and open-drain reset connection - the details that decide whether a 5 V system powers up and recovers cleanly.