STMicroelectronics STM6720TZWB6F

Overview

STM6720TZWB6F from STMicroelectronics is a dual ultra-low voltage supervisor IC with push-button reset, primary (VCC1) and secondary (VCC2) supply monitoring, adjustable RSTIN input (0.626 V reference), active-low push-pull RST output, and 900 ms typical power-on reset delay (trec). It operates from –40 °C to +85 °C and draws only 11 µA at 3.6 V, targeting battery-powered embedded systems requiring reliable multi-rail power sequencing and manual reset.

For engineers reviewing the STM6720TZWB6F datasheet, STM6720TZWB6F pinout, STM6720TZWB6F application, or STM6720TZWB6F equivalent, key selection criteria include its SOT23-6 package, factory-trimmed VCC1 threshold (1.58 V), VCC2 threshold (0.79 V), guaranteed RST validity down to 0.8 V supply, and compatibility with bi-directional processor reset interfaces via external series resistor.

Technical Context

The STM6720 implements independent comparators for VCC1 (primary rail) and VCC2 (secondary rail), each with factory-programmed reset thresholds-1.58 V and 0.79 V respectively-and a third high-impedance RSTIN input referenced to an internal 0.626 V bandgap. All three inputs feed into logic that asserts RST low if any falls below its threshold or if MR is pulled low.

RST is a push-pull active-low output referenced to VCC1, guaranteed functional when VCC1 ≥ 0.8 V or VCC2 ≥ 0.8 V. Reset release is delayed by a fixed 900 ms (typ) after all monitored supplies exceed thresholds and MR returns high, ensuring stable power-up before system release.

Key Specifications

Pinout & Package

SOT23-6 (WB) package: 6-pin surface-mount, 1.3 mm × 2.9 mm footprint, 1.45 mm height, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply supervisor applications.

Compared with TPS3808G33DBVR and MAX6326UR29D3+T, the STM6720TZWB6F uniquely delivers triple-rail supervision (two fixed + one adjustable), push-pull RST, and 900 ms delay in SOT23-6-enabling compact, robust power sequencing where multiple voltage domains must be coordinated.

Availability

STM6720TZWB6F is available at Aetrix Electronics and suitable for portable medical devices, industrial PLC modules, set-top boxes, and automotive infotainment systems requiring stable component supply, long-term lifecycle support, and guaranteed industrial-temperature operation.

Supply support for STM6720TZWB6F includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and analog products for industrial, automotive, and consumer markets.

The STM67xx family was developed specifically for ultra-low-power, multi-rail voltage supervision in space-constrained embedded systems-emphasizing factory-trimmed accuracy, guaranteed low-VCC operation, and minimal external component count.

FAQ

What is the function of the RSTIN pin on STM6720TZWB6F?

The RSTIN pin is a high-impedance input referenced to an internal 0.626 V bandgap voltage. When the external voltage applied to RSTIN falls below this threshold, the RST output is driven low. It enables supervision of a third voltage rail-such as a core supply or battery voltage-using a simple resistor divider network connected between the rail and ground, with RSTIN tied to the midpoint.

Can STM6720TZWB6F operate with VCC1 below 1.58 V?

Yes-the device guarantees correct RST output logic state as long as VCC1 or VCC2 is ≥ 0.8 V. While the 1.58 V threshold defines the point at which VCC1 faults trigger reset, the IC remains fully functional and maintains valid RST assertion/deassertion down to 0.8 V. Below 0.8 V, RST behavior is undefined per datasheet specifications.

How does the manual reset (MR) interact with the power-on reset delay?

When MR is asserted low, RST immediately goes low and remains low for the full 900 ms (typ) delay period after MR returns high-regardless of VCC1/VCC2 status. This ensures consistent reset duration for both power-up and manual events, simplifying system-level timing analysis and eliminating need for separate debounce or timing circuits.

Is STM6720TZWB6F pin-compatible with other STM67xx variants?

No-STM6720TZWB6F uses the SOT23-6 (WB) package with pins RST/VCC1/VCC2/MR/RSTIN/VSS. It is not pin-compatible with SOT23-5 variants (e.g., STM6717) or with STM677x parts that include MRC. Pin mapping differs across the family; PCB layout must match the exact variant's pinout table (Table 3 in datasheet Doc ID 11469 Rev 8).