NXP Semiconductors MC32BC3770CSR2

Overview

MC32BC3770CSR2 from NXP Semiconductors is a fully programmable 2.0 A synchronous switch-mode Li-ion battery charger with intelligent dual-path power delivery, integrated OVP and power FETs, 1.5 MHz switching frequency, and I²C-programmable charge parameters (fast-charge current up to 2000 mA, regulation voltage 4.1–4.475 V). It enables system boot from dead battery in handheld consumer devices.

For engineers reviewing the MC32BC3770CSR2 datasheet, MC32BC3770CSR2 pinout, MC32BC3770CSR2 application, or MC32BC3770CSR2 equivalent, key selection considerations include its 20 V input tolerance, thermal regulation at 100 °C, VSYS output tracking capability, and WLCSP-25 package compatibility with space-constrained IoT and wearable designs.

Technical Context

The MC32BC3770CSR2 integrates a buck charger and boost regulator sharing a 1.5 MHz PWM controller, enabling simultaneous system power (VSYS) and battery charging (CHGOUT) with intelligent power-path arbitration. Its dual-path architecture uses Q4 (30 mΩ) to dynamically route power between battery and system load based on VBUS presence and VSYS regulation state.

It implements adaptive input current limiting (AICL) with programmable 4.3–4.9 V threshold, thermal regulation that linearly reduces fast-charge current above 100 °C (3.33 %/°C), and safety timers for trickle (45 min), pre-charge (45 min), and fast-charge (3.5–5.5 hr) modes - all configurable via 400 kHz I²C interface with register-level control of CV/CC thresholds, recharge voltage, and weak-battery detection.

Key Specifications

Pinout & Package

The MC32BC3770CSR2 is housed in a 25-bump, 2.27 mm × 2.17 mm, 0.4 mm pitch Wafer-Level Chip-Scale Package (WLCSP), optimized for high-density portable applications with minimal board area and thermal resistance (θ_JA = 48 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery charger applications.

Compared with BQ25618RTWR and MP2617GQZ, the MC32BC3770CSR2 uniquely combines 2.0 A charging, 1.5 MHz high-frequency operation, integrated OTG boost, and true dual-path power delivery in a 2.27 mm × 2.17 mm WLCSP - enabling smaller form factors and faster system wake-up without compromising safety or configurability.

Availability

MC32BC3770CSR2 is available at Aetrix Electronics and suitable for handheld consumer devices, wearable electronics, IoT edge nodes, and mPOS terminals requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MC32BC3770CSR2 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

NXP Semiconductors is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and mobile applications, with core expertise in power management and mixed-signal integration.

The BC3770 product line was designed specifically for space-constrained, battery-powered portable electronics requiring intelligent power-path management, fast charging, and seamless dead-battery boot - targeting next-generation wearables, IoT sensors, and compact consumer devices.

FAQ

What is the maximum input voltage the MC32BC3770CSR2 can withstand?

The MC32BC3770CSR2 has an absolute maximum input voltage rating of 20 V on the VBUS pin, with operational input range specified from 4.0 V to 6.2 V. This 20 V tolerance provides robust protection against USB-C transients and adapter surges while enabling compatibility with wide-input USB/DCP sources. The device incorporates internal OVP circuitry that disables the converter if VBUS exceeds 6.7 V (typical), ensuring safe operation under fault conditions.

How does the MC32BC3770CSR2 handle charging from a completely dead battery?

The MC32BC3770CSR2 enables system boot from a dead battery (<2.5 V) using its dual-path architecture: when VBUS is applied, VSYS powers the host processor immediately while the charger initiates trickle mode (90 mA) on CHGOUT. This allows the system to initialize and configure charge parameters via I²C before transitioning to pre-charge and fast-charge stages - a capability confirmed in the functional description and Figure 1 application diagram of the MC32BC3770CSR2 datasheet.

What is the purpose of the NOBAT pin on the MC32BC3770CSR2?

NOBAT is a logic input pin on the MC32BC3770CSR2 used for battery presence detection. It features an internal 300 kΩ pull-up to VL and suspends charging immediately if a logic-high threshold is detected - indicating either missing battery or faulty pack communication. When unused, it must be tied to ground per datasheet guidance. This pin directly controls charger enablement independent of I²C commands, providing hardware-level safety for battery insertion validation.

Can the MC32BC3770CSR2 operate as a USB On-The-Go (OTG) power source?

Yes, the MC32BC3770CSR2 supports USB OTG functionality by operating as a boost regulator to generate 5.0–5.2 V at PMID, delivering up to 900 mA. Activation is possible via I²C command or assertion of the CHGENB pin, with regulation accuracy of ±250 mV over load and battery voltage ranges. This capability is explicitly documented in Section 5.2 "Features" and Table 4 electrical characteristics under "Boost converter" parameters.

What thermal protection mechanisms does the MC32BC3770CSR2 implement?

The MC32BC3770CSR2 implements two-tier thermal protection: hard shutdown at 150 °C (TSD) and active thermal regulation starting at 100 °C (TCF), where fast-charge current is linearly reduced at 3.33 %/°C to maintain system power (VSYS) while preventing battery damage. Both thresholds and the regulation slope are guaranteed by design and characterization per datasheet Note 11, and status is reported via INTB interrupt.