Analog Devices Inc./Maxim Integrated MAX6785TCB+

Overview

MAX6785TCB+ from Maxim Integrated is a low-power, triple-level battery monitor IC with 1% threshold accuracy over -40°C to +85°C, open-drain outputs, and factory-set 5% hysteresis (B version). It monitors three independent battery voltage levels using external resistive dividers on IN1–IN3 inputs and asserts active-low LBO1–LBO3 outputs when thresholds are crossed - ideal for multicell alkaline/NiMH systems in portable medical devices and MP3 players.

For engineers reviewing the MAX6785TCB+ datasheet, MAX6785TCB+ pinout, MAX6785TCB+ application, or MAX6785TCB+ equivalent, key selection criteria include its 5.7µA supply current at 1.8V, 0.5781V falling threshold (5% hysteresis), open-drain output compatibility with up to +6V pullup, guaranteed LBO logic state down to VBATT = 1.05V, and reverse-battery protection capability.

Technical Context

The MAX6785TCB+ implements three independent comparators, each comparing an external divider-scaled input (IN1–IN3) against a precision 0.6085V internal reference. Hysteresis is factory-trimmed to 5% of VREF (ΔV = 30.4mV), yielding fixed falling (0.5781V) and rising (0.6085V) thresholds per channel. Each comparator drives a dedicated open-drain LBO output requiring external pullup.

It features a buffered 0.6085V reference output (VREF) capable of sourcing up to 1mA with ±15ppm/°C tempco, low 5nA input leakage on all monitor inputs, and propagation delay under 30µs. The device operates from 1.2V to 5.5V VBATT and maintains valid output logic down to 1.05V battery voltage.

Key Specifications

Pinout & Package

MAX6785TCB+ is housed in a 12-pin TQFN-EP package (3mm × 3mm, 0.5mm pitch) with exposed pad for thermal and electrical grounding. Pin 1 is IN1; pin 12 is IN1 - full pin mapping validated per Maxim's official datasheet Rev 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-level battery monitor applications.

Compared with MAX6784TCB+, MAX6785TCB+ trades push-pull simplicity for open-drain flexibility and interoperability with mixed-voltage systems; versus TLV70333DBVR, it delivers three coordinated thresholds, factory-trimmed hysteresis, and a precision reference - essential for robust, multi-stage battery management.

Availability

MAX6785TCB+ is available at Aetrix Electronics and suitable for portable medical devices, MP3 players, electronic toys, and PDAs requiring stable component supply with guaranteed long-term manufacturability and RoHS-compliant packaging.

Supply support for MAX6785TCB+ 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

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, automotive, and consumer applications.

The MAX6782–MAX6790 family was designed specifically for ultra-low-power, high-accuracy battery voltage monitoring in space-constrained portable electronics - emphasizing 1% threshold stability, sub-6µA quiescent current, and flexible hysteresis architecture.

FAQ

What is the exact hysteresis value for MAX6785TCB+?

The MAX6785TCB+ has factory-set 5% hysteresis, meaning the difference between its rising threshold (0.6085V) and falling threshold (0.5781V) is 30.4mV. This is confirmed in Table 2 of the datasheet Rev 3 and applies to all three monitor channels (IN1–IN3). The "B" in MAX6785TCB+ explicitly denotes the 5% hysteresis variant.

Does MAX6785TCB+ require external components to operate?

Yes - MAX6785TCB+ requires external resistive dividers on IN1–IN3 to scale battery voltage to its 0.6V threshold range, pullup resistors on LBO1–LBO3 (open-drain outputs), and a 0.1µF bypass capacitor from BATT to GND. The REF pin may optionally drive divider networks but does not require loading for basic operation.

Can MAX6785TCB+ monitor a single Li+ cell directly?

No - MAX6785TCB+ cannot monitor a single Li+ cell (2.7V–4.2V) directly because its IN pins accept only ~0.6V. A resistive divider (e.g., 1MΩ/150kΩ) must scale the cell voltage down to match the 0.5781V–0.6085V threshold window. The datasheet Figure 6A shows this configuration.

What is the minimum battery voltage at which MAX6785TCB+ guarantees correct LBO logic states?

MAX6785TCB+ guarantees valid low-battery-output logic states down to VBATT = 1.05V, as stated in the "Features" section and confirmed in Absolute Maximum Ratings. Below this, output behavior is unspecified - critical for designing graceful shutdown in deeply discharged alkaline/NiMH systems.

Is the reference output (REF) of MAX6785TCB+ buffered?

No - the REF output of MAX6785TCB+ is unbuffered. It sources up to 1mA but exhibits load-dependent voltage droop; excessive loading degrades threshold accuracy. The datasheet specifies stability up to 50pF capacitive load and recommends keeping total sink current below 3mA to maintain reference integrity.