rd-bq24210 typeCAD Package

bq24210 Datasheet

bq24210 800-mA, Single-Input, Single-Cell Li-Ion Battery Solar Charger

This is the Reference Design of the bq24210 in Section 9.2 Typical Application of the datasheet.

Features

• 20-V Input Rating, With Overvoltage Protection
• 1% Battery Voltage Regulation Accuracy
• Programmable fast charge current (50mA to 800mA)
• Input voltage dynamic power management (VBUS-DPM)
• Battery tracking mode for solar panel compatibility
• Temperature monitoring with NTC thermistor support
• Auto-enabling charging operations (EN tied to PG)

Installation

npm i @typecad/rd-bq24210

Components

The package includes:

• U1: BQ24210DQCR main IC
• C1: VBUS bypass capacitor (1µF)
• C2: BAT bypass capacitor (1µF)
• R_ISET: Fast charge current setting resistor (calculated based on chargeCurrentMa)
• RT1: Temperature sensing resistor (21.5kΩ, optional)

External Connections Required

• VBUS: Input power source (3.5V to 18V)
• BAT: Battery connection and system load
• VSS/EP: Ground connection
• CHG: Connect LED with series resistor for charge status (optional)
• PG: Connect LED with series resistor for power good status (optional)

Usage

Basic Usage

import { PCB } from '@typecad/typecad';
import { rd_bq24210 } from '@typecad/rd-bq24210';

// Create PCB instance
let typecad = new PCB('my_charger_board');

// Create the charger module
let charger = new rd_bq24210({ 
  chargeCurrentMa: 500,
  temperatureMonitoring: true,
  pcb: typecad 
});

// Connect power source
typecad.net(solarPanel.positive, charger.U1.VBUS);
typecad.net(solarPanel.negative, charger.U1.VSS);

// Connect battery
typecad.net(battery.positive, charger.U1.BAT);
typecad.net(battery.negative, charger.U1.VSS);

Constructor Parameters

interface Ird_bq24210 {
    chargeCurrentMa?: number;        // Fast charge current in mA (default: 500mA)
    temperatureMonitoring?: boolean; // Enable temperature monitoring (default: true)
    passives?: typeof _0603;         // Passive component library (default: 0603)
    pcb: PCB;                       // PCB instance (required)
}

Custom Charge Current

let charger = new rd_bq24210({
  chargeCurrentMa: 750,  // Set charge current to 750mA
  pcb: typecad
});

The charge current resistor (R_ISET) is automatically calculated using:

R_ISET = 390 / (chargeCurrentMa / 1000)

Disable Temperature Monitoring

let charger = new rd_bq24210({
  temperatureMonitoring: false,  // Disables RT1 resistor
  pcb: typecad
});

Custom Passives

The default size for the passive components is 0603, but it can be changed:

import * as _0805 from '@typecad/passives/0805';

let charger = new rd_bq24210({
  passives: _0805,
  pcb: typecad
});

Accessing Components

All components are accessible as properties:

// Access the main IC
let ic = charger.U1;

// Access passive components
let vbusCap = charger.C1;
let batCap = charger.C2;
let isetRes = charger.R_ISET;
let tempRes = charger.RT1; // undefined if temperatureMonitoring is false

// Access all components array
let allComponents = charger.components;

Design Considerations

Temperature Monitoring

The bq24210 uses a voltage divider with RT1 to monitor battery temperature with a 10kΩ NTC thermistor at 25°C.

When Temperature Monitoring is Enabled (default: true)

let charger = new rd_bq24210({
  temperatureMonitoring: true,  // Default behavior
  pcb: typecad
});

A 10K NTC must be used in the circuit.

When Temperature Monitoring is Disabled

let charger = new rd_bq24210({
  temperatureMonitoring: false,
  pcb: typecad
});

results in placing a 10K resistor to simulate the battery temperature at a constant 25°C.

Recommended: Keep temperatureMonitoring enabled and add your NTC in parallel with the default RT1 for safe operation.

VDPM (Dynamic Power Management)

The VDPM pin is left floating in this implementation, enabling battery tracking mode which is ideal for solar panel applications.

Auto-Enable

The EN pin is tied to the PG pin, automatically enabling charging when input power is present.

Thermal Management

The thermal pad (EP) is connected to ground for optimal heat dissipation.

Default Component Placement

The package includes default component placement coordinates optimized for the reference design layout. Components are automatically positioned when the rd_bq24210 class is instantiated.

Electrical Connections

The package automatically creates these internal connections:

• VBUS bypass capacitor (C1): VBUS to VSS
• BAT bypass capacitor (C2): BAT to VSS
• Current setting resistor (R_ISET): ISET to VSS
• Auto-enable: EN tied to PG
• Temperature monitoring (if enabled): VTSB to TS via RT1
• Thermal pad: EP to VSS