MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications General Description Features The MAX1501 intelligent, constant-current, constantvoltage (CCCV), temperature-regulated battery charger charges a single lithium-ion (Li+) cell or three-cell NiMH/NiCd batteries. The device integrates the currentsense resistor, PMOS pass element, and thermalregulation circuitry, while eliminating the reverseblocking Schottky diode to create the simplest charging solution for hand-held equipment. o Stand-Alone 1-Cell Li+ Charging, MicroprocessorControlled 3-Cell NiMH/NiCd Charging o No FET, Reverse-Blocking Diode, or CurrentSense Resistor Required For single-cell Li+ batteries, the MAX1501 functions as a stand-alone charger to control the charging sequence from the prequalification state through fast charge, topoff, and charge termination. With 3-cell NiMH/NiCd batteries, the MAX1501 requires collaboration with a microcontroller to determine the best charging algorithm. Proprietary thermal-regulation circuitry limits the die temperature when fast charging or while exposed to high ambient temperatures, allowing maximum charging current without damaging the charger. The MAX1501 continually supplies a regulated output voltage under no-battery conditions, allowing battery changing without interrupting system power. The device achieves high flexibility by providing an adjustable fast-charge current, top-off current, safety timer (disabled in the MAX1501Z), and thermal-regulation setpoint. Other features include input power detection (ACOK) and input under-/overvoltage protection. The MAX1501 provides active-low control inputs. The MAX1501 accepts a 4.5V to 13V supply, but disables charging when the input voltage exceeds 6.5V, preventing excessive power dissipation. The MAX1501 operates over the extended temperature range (-40C to +85C) and is available in a compact 16-pin thermally enhanced 5mm x 5mm thin QFN package with 0.8mm profile. o 1.4A (max) Programmable Fast-Charge Current o +95C, +115C, and +135C Proprietary Programmable Die Temperature Regulation Control o 4.5V to 13V Input Voltage Range with Input Overvoltage (OVLO) Protection Above 6.5V o Programmable Top-Off Current Threshold: 10%, 20%, or 30% of the Fast-Charge Current o Charge-Current Monitor for Fuel Gauging o Programmable Safety Timer (3, 4.5, or 6 hours) o Input Power Detection Output (ACOK) and Charge Enable Input (CHGEN) o Automatic Recharge o Digital Soft-Start Limits Inrush Current o Charge Status Outputs for LEDs or P Interface Ordering Information TEMP RANGE PIN-PACKAGE MAX1501ETE PART -40C to +85C 16 Thin QFN MAX1501ZETE -40C to +85C 16 Thin QFN Typical Operating Circuit INPUT 4.5V TO 13V 4.2V 1-CELL Li+ IN 1F BATT 10F INP Applications MAX1501/MAX1501Z Cellular and Cordless Phones FULLI PDAs Digital Cameras and MP3 Players USB Appliances Charging Cradles and Docks GLED VL RLED SELV TEMP MODE TMAX/I.C. BluetoothTM Equipment CHGEN RPULLUP SETI ACOK 2.8k Pin Configuration appears at end of data sheet. VLOGIC ( 5.5V) GND Bluetooth is a trademark of Ericsson. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maximintegrated.com. 19-2800; Rev 2; 4/14 MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications ABSOLUTE MAXIMUM RATINGS IN, INP, RLED, GLED to GND ................................-0.3V to +14V IN to INP ................................................................-0.3V to +0.3V VL, BATT, SETI, ACOK, MODE, CHGEN, SELV, FULLI, TMAX/I.C., TEMP to GND .........................-0.3V to +6V VL to IN...................................................................-14V to +0.3V Continuous Power Dissipation (TA = +70C) 16-Pin 5mm 5mm Thin QFN (derate 21.3mW/C above +70C) .............................1702mW Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VIN = VINP = 5V, VBATT = 3.5V, ACOK = GLED = RLED = TEMP = TMAX/I.C. = FULLI = open, CHGEN = MODE = GND, RSETI = 2.8k, CIN = 1F, CBATT = 10F, TA = 0C to +85C, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER CONDITIONS IN, INP Input Voltage IN, INP Input Operating Range MIN TYP MAX 13 V 4.50 6.25 V V 4.5V VIN 6.25V, IVL < 250A 2.7 3 3.3 VIN - VBATT, rising 40 70 100 ACOK Trip Point VIN - VBATT, falling 30 55 85 ACOK Sink Current 4.5V VIN 6.25V, V ACOK = 0.6V VL Output Voltage VIN - VBATT, hysteresis A 4.05 4.125 4.20 Undervoltage Lockout Trip Point VIN falling 3.9 4.025 4.1 Overvoltage Lockout Trip Point VIN rising 6.25 6.50 6.75 5 8 1.5 3 Hysteresis 100 Li+, NiMH/NiCd, and no-battery modes Disable mode Off mode (VIN = 4V) 80 BATT Input Current VIN = 0 3 10 2 6 Leakage into Battery VIN = VINP = 13V, VBATT = 0 Disable mode Disable mode RMS Charge Current NiMH/NiCd mode V mA 0.25 45 Battery Regulation Voltage V mV VBATT = 4.3V Li+ mode mV 15 75 VIN rising IN Input Current UNITS 0 5 A 1.4 A SELV = VL 4.166 4.2 4.234 SELV = GND 4.067 4.1 4.133 SELV = VL, VIN = VINP = 6V 4.85 4.95 5.05 SELV = GND A V 4.4 4.5 4.6 Output Regulation Voltage No-battery mode 3.700 4.0 4.234 V BATT Precharge Threshold Voltage BATT rising 2.675 2.8 2.925 V RSETI = 2.8k 460 500 540 RSETI = 1.75 k 736 800 864 Fast-Charge Current-Loop System Accuracy 2 mA Maxim Integrated MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications ELECTRICAL CHARACTERISTICS (continued) (VIN = VINP = 5V, VBATT = 3.5V, ACOK = GLED = RLED = TEMP = TMAX/I.C. = FULLI = open, CHGEN = MODE = GND, RSETI = 2.8k, CIN = 1F, CBATT = 10F, TA = 0C to +85C, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER Precharge Current System Accuracy Die Temperature Regulation Setpoint (Note 1) CONDITIONS % of fast-charge current, VBATT = 2V MIN TYP MAX UNITS 5 10 15 % TEMP = GND 95 TEMP = open 115 TEMP = VL Current-Sense Amplifier Gain 0.70 1 1.30 IBATT to ISETI, fast-charge mode 0.95 1 1.05 84 Regulator Dropout Voltage VIN - VBATT, NiMH/NiCd mode, VBATT = 4.3V, IBATT = 425mA Logic Input Low Voltage CHGEN, MODE, 4.5V VIN 6.25V Logic Input High Voltage CHGEN, MODE, 4.5V VIN 6.25V 1.25 Internal Pulldown Resistance CHGEN, MODE 100 Internal Pullup Resistance SELV 100 Internal Bias Resistance FULLI, TEMP, TMAX 50 Internal Bias Voltage FULLI, TEMP, TMAX RLED Output Low Current V RLED = 1V 7 GLED Output Low Current V GLED = 1V 14 GLED, RLED Output High Leakage Current V GLED = V RLED = VIN = VINP = 13V Full-Battery Detection Current Threshold % of fast-charge current Li+ mode NiMH/NiCd mode Charge-Timer Accuracy Charge-Timer Duration (MAX1501 Only) Maxim Integrated 190 mA/A m 350 mV 0.52 V 175 400 k 175 400 k 90 200 k 10 18 mA 20 34 mA 0.1 1 A 15 V VVL/2 V FULLI = GND 5 10 FULLI = VL 15 20 25 FULLI = open 25 30 35 SELV = VL 3.9 4.0 4.1 SELV = GND 3.8 3.9 4.0 3.9 4.0 4.1 -10 +10 TMAX = GND 3 TMAX = open 4.5 TMAX = VL C 135 IBATT to ISETI, precharge mode, VBATT = 2V Internal Current-Sense Resistance VBATT Restart Threshold o % V % hrs 6 3 MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications ELECTRICAL CHARACTERISTICS (VIN = VINP = 5V, VBATT = 3.5V, ACOK = GLED = RLED = TEMP = TMAX/I.C. = FULLI = open, CHGEN = MODE = GND, RSETI = 2.8k, CIN = 1F, CBATT = 10F, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = +25C.) (Note 2) PARAMETER CONDITIONS IN, INP Input Voltage ACOK Trip Point ACOK Sink Current Undervoltage Lockout Trip Point BATT Input Current Leakage into Battery UNITS 13 V 6.25 V 4.5V VIN 6.25V, IVL < 250A 2.7 3.3 V VIN - VBATT, rising 40 100 VIN - VBATT, falling 30 85 4.5V VIN 6.25V, V ACOK = 0.6V 75 4.00 4.25 VIN falling 3.90 4.15 6.25 6.75 Li+, NiMH/NiCd, and no-battery modes 8 Disable mode 3 VBATT = 4.3V 80 VIN = 0 10 Disable mode 6 VIN = VINP = 13V, VBATT = 0 Disable mode Li+ mode Battery Regulation Voltage NiMH/NiCd mode SELV = VL 4.148 mV A VIN rising RMS Charge Current V V mA A 5 A 1.4 A 4.252 SELV = GND 4.05 4.15 SELV = VL 4.85 5.05 SELV = GND 4.4 4.6 V Output Regulation Voltage No-battery mode 3.700 4.234 V BATT Precharge Threshold Voltage BATT rising 2.675 2.925 V RSETI = 2.8k 460 540 RSETI = 1.75k 736 864 5 15 Fast-Charge Current-Loop System Accuracy Precharge Current System Accuracy Current-Sense Amplifier Gain 4 MAX 0 Overvoltage Lockout Trip Point IN Input Current TYP 4.50 IN, INP Input Operating Range VL Output Voltage MIN % of fast-charge current, VBATT = 2V IBATT to ISETI, precharge mode, VBATT = 2V 0.60 1.40 IBATT to ISETI, fast-charge mode 0.93 1.07 mA % mA/A Regulator Dropout Voltage VIN - VBATT, NiMH/NiCd mode, VBATT = 4.3V, IBATT = 425mA 350 mV Logic Input Low Voltage CHGEN, MODE, 4.5V < VIN < 6.25V 0.52 V Logic Input High Voltage CHGEN, MODE, 4.5V < VIN < 6.25V 1.3 Internal Pulldown Resistance CHGEN, MODE 100 400 k Internal Pullup Resistance SELV 100 400 k Internal Bias Resistance FULLI, TEMP, TMAX 50 200 k V Maxim Integrated MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications ELECTRICAL CHARACTERISTICS (continued) (VIN = VINP = 5V, VBATT = 3.5V, ACOK = GLED = RLED = TEMP = TMAX/I.C. = FULLI = open, CHGEN = MODE = GND, RSETI = 2.8k, CIN = 1F, CBATT = 10F, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = +25C.) (Note 2) MAX UNITS RLED Output Low Current PARAMETER V RLED = 1V CONDITIONS MIN 7 18 mA GLED Output Low Current V GLED = 1V 14 34 mA GLED, RLED Output High Leakage Current V GLED = V RLED = VIN = VINP = 13V 1 A +10 % Charge-Timer Accuracy (MAX1501 Only) TYP -10 Note 1: Temperature regulation setpoint variation is typically 9C. Note 2: Specifications to TA = -40C are guaranteed by design, not production tested. Typical Operating Characteristics (VIN = VINP = 5V, ACOK = RLED = GLED = TEMP = TMAX/I.C. = FULLI = open, CBATT = 10F, CIN = 1F, TA = +25C, unless otherwise noted.) DISABLE-MODE SUPPLY CURRENT vs. INPUT VOLTAGE 2.5 2.0 1.5 1.0 0.5 0 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 300 250 200 150 100 50 0 INPUT VOLTAGE (V) BATTERY VOLTAGE (V) CHARGE CURRENT vs. BATTERY VOLTAGE CHARGE CURRENT vs. INPUT VOLTAGE CHARGE CURRENT vs. INPUT-VOLTAGE HEADROOM 400 350 300 250 200 150 100 50 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 BATTERY VOLTAGE (V) Maxim Integrated 600 550 500 450 0 Li+ MODE, SELV = VL, RSETI = 2.7k 400 350 300 250 200 150 100 50 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 INPUT VOLTAGE (V) 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 600 550 CHARGE CURRENT (mA) CHARGE CURRENT (mA) 500 450 MAX1501 toc04 0 1 2 3 4 5 6 7 8 9 10 11 12 13 INPUT VOLTAGE (V) NiMH/NiCd, RSETI = 2.7k, VIN = 5.5V, SELV = VL MAX1501 toc03 400 350 0 1 2 3 4 5 6 7 8 9 10 11 12 13 600 550 CHARGE CURRENT (mA) 1.6 Li+ MODE, RSETI = 2.7k, VIN = 5V, SELV = VL 550 500 450 500 450 NiMH/NiCd MODE, SELV = GND, RSETI = 2.7k, VBATT = 4.3V 400 MAX1501 toc06 3.0 600 CHARGE CURRENT (mA) 3.5 1.8 MAX1501 toc05 SUPPLY CURRENT (mA) 4.0 2.0 CHARGE CURRENT vs. BATTERY VOLTAGE MAX1501 toc02 Li+ MODE OR NiMH/NiCd MODE, SELV = VL, IBATT = 0 4.5 DISABLE-MODE SUPPLY CURRENT (mA) 5.0 MAX1501 toc01 SUPPLY CURRENT vs. INPUT VOLTAGE 350 300 250 200 150 100 50 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 VIN - VBATT (V) 5 MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications Typical Operating Characteristics (continued) (VIN = VINP = 5V, ACOK = RLED = GLED = TEMP = TMAX/I.C. = FULLI = open, CBATT = 10F, CIN = 1F, TA = +25C, unless otherwise noted.) BATTERY REGULATION VOLTAGE vs. TEMPERATURE 3.0 2.5 2.0 1.5 1.0 0.5 Li+ MODE 0 4.20 4.16 4.14 4.12 4.08 10 35 60 CHARGE CURRENT vs. AMBIENT TEMPERATURE CHARGE CURRENT vs. AMBIENT TEMPERATURE 1000 MAX1501 toc09 Li+ MODE, TEMP = VL, VBATT = 3.6V, VIN = 5V, RSETI = 2.7k 900 800 CHARGE CURRENT (mA) CHARGE CURRENT (mA) -15 TEMPERATURE (C) 540 520 500 480 460 700 600 85 Li+ MODE, TEMP = VL, VBATT = 3.6V, VIN = 6V, RSETI = 1.75k 500 400 300 440 200 420 100 400 0 -40 -15 10 35 60 AMBIENT TEMPERATURE (C) 6 -40 INPUT VOLTAGE (V) 600 560 SELV = GND 4.10 0 1 2 3 4 5 6 7 8 9 10 11 12 13 580 SELV = VL 4.18 MAX1501 toc10 OUTPUT VOLTAGE (V) 3.5 4.22 MAX1501 toc08 NO BATTERY MODE IBATT = 0 BATTERY REGULATION VOLTAGE (V) 4.0 MAX1501 toc07 OUTPUT VOLTAGE vs. INPUT VOLTAGE 85 -40 -15 10 35 60 85 AMBIENT TEMPERATURE (C) Maxim Integrated MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications Pin Description PIN NAME 1 INP 2 IN 3, 13 GND Ground. Connect the exposed paddle to GND. 4 SETI Current-Sense Transconductance Amplifier Output. Connect a resistor from SETI to GND to program the maximum charge current and to monitor the actual charge current. SETI pulls to GND during shutdown. 5 VL Linear Regulator Output. Connect CHGEN, TEMP, TMAX, FULLI, and MODE to VL to program logic high. VL discharges to GND during shutdown. TMAX Maximum Charging-Time Select Input (MAX1501 Only). TMAX sets the maximum charging time. Connect TMAX to GND to set the maximum charging time to 3 hours. Leave TMAX floating to set the maximum charging time to 4.5 hours. Connect TMAX to VL to set the maximum charging time to 6 hours. TMAX pulls to GND through a 50k resistor in shutdown. 6 I.C. FUNCTION High-Current Charger Input. Connect an AC adapter to INP and IN as close to the device as possible. INP provides charge current to the battery. INP draws current while the device is in shutdown mode. Low-Current Charger Input. Bypass IN to GND with a 1F ceramic capacitor. Connect IN to INP as close to the device as possible. IN powers the internal LDO and reference. IN draws current while the device is in shutdown mode. Internally Connected in the MAX1501Z. Leave floating. FULLI Top-Off-Current Select Input. FULLI sets the end-of-charge threshold as a percentage of the fast-charge current. Connect FULLI to GND to set the end-of-charge threshold to 10% of the fast-charge current. Connect FULLI to VL to set the end-of-charge threshold to 20% of the fast-charge current. Leave FULLI floating to set the end-of-charge threshold to 30% of the fast-charge current. FULLI pulls to GND through a 50k resistor in shutdown. 8 TEMP Die Temperature Select Input. TEMP sets the die temperature regulation point for the thermal-control loop. Connect TEMP to GND to regulate the die temperature at +95C. Leave TEMP floating to regulate the die temperature at +115C. Connect TEMP to VL to regulate the die temperature at +135C. TEMP pulls to GND through a 50k resistor in shutdown. 9 MODE Mode Select Input. MODE and CHGEN together control charging functions (Table 1). An internal 175k pulldown resistor pulls MODE low. 10 CHGEN 11 ACOK Input Voltage Range Indicator. The open-drain ACOK output asserts low when 4.2V VIN 6.25V and VIN - VBATT 100mV. ACOK requires an external 100k pullup resistor. ACOK floats in shutdown. 12 BATT Battery Connection. Connect the positive terminal of the battery to BATT. BATT draws less than 5A during shutdown. 14 SELV Battery Voltage Selection Input. SELV sets the battery regulation voltage in Li+ and NiMH/NiCd modes (Table 2). For no-battery mode, the battery voltage defaults to 4.0V. An internal 175k resistor to VL pulls SELV high. RLED Battery Charging Indicator. Connect the anode of a red LED to IN and the cathode to RLED. RLED asserts low when the input supply is present and the battery is charging, regardless of cell chemistry. RLED sinks 10mA. RLED goes high impedance in shutdown. Connect a pullup resistor to the P's I/O supply when interfacing with a P logic input. GLED Full-Charge Indicator. Connect the anode of a green LED to IN and the cathode to GLED. GLED asserts low when the input supply is present and the battery has reached the top-off current threshold set by FULLI, regardless of cell chemistry. GLED sinks 20mA. GLED goes high impedance in shutdown. Connect a pullup resistor to the P's I/O supply when interfacing with a P logic input. 7 15 16 Maxim Integrated Charge Enable Input. CHGEN and MODE together control charging functions (Table 1). An internal 175k pulldown resistor pulls CHGEN low. 7 MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications MAX1501/MAX1501Z INP BATT VREF CS OUTPUT DRIVER AND LOGIC SETI TEMP REF TEMPERATURE SENSOR IREF IN SHUTDOWN UVLO VL CHGEN VL MODE REF SELV OVLO ON LOGIC TEMP ACOK RLED FULLI GLED OSC GND TMAX/I.C. GND Figure 1. Functional Diagram 8 Maxim Integrated MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications MAX1501 ONLY OFF ACOK = HIGH CHARGER OFF ACOK = LOW RLED = OFF GLED = OFF ACOK = (4.2V < VIN < 6.25V) AND (VIN - VBATT > 100mV) ACOK = LOW CHGEN = LOW VBATT < 2.8V CHGEN = HIGH MODE = LOW PREQUAL DISABLE CHARGER OFF ACOK = LOW RLED = OFF GLED = OFF CHGEN = LOW 10% SETI CURRENT ACOK = LOW RLED = ON GLED = OFF SOFT-START NOBATT (CURRENT LIMITED AND CHGEN = LOW THERMALLY PROTECTED) ACOK = LOW RLED = OFF GLED = OFF CHGEN = HIGH MODE = HIGH SOFT-START VBATT < 2.8V FAST CHARGE (THERMALLY PROTECTED) 100% SETI CURRENT ACOK = LOW RLED = ON GLED = OFF ICHG < ITOP-OFF TIME > TMAX VBATT < 4V (Li+ MODE, SELV = VL, AND NiMH/NiCd MODE) VBATT < 3.9V (Li+ MODE, SELV = GND) TOP OFF (VOLTAGE LOOP) RLED = OFF GLED = ON TIME > TMAX DONE CHARGER OFF RLED = OFF GLED = ON Figure 2. MAX1501 Charge State Diagram Maxim Integrated 9 MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications MAX1501Z ONLY OFF ACOK = HIGH CHARGER OFF ACOK = LOW RLED = OFF GLED = OFF ACOK = (4.5V < VIN < 6.5V) AND (VIN > VBATT) ACOK = LOW CHGEN = LOW VBATT < 2.8V CHGEN = HIGH MODE = LOW NOBATT DISABLE PREQUAL CHARGER OFF ACOK = LOW RLED = OFF GLED = OFF 10% SETI CURRENT ACOK = LOW RLED = ON GLED = OFF CHGEN = LOW SOFT-START CHGEN = HIGH MODE = HIGH (CURRENT LIMITED AND CHGEN = LOW THERMALLY PROTECTED) ACOK = LOW RLED = OFF GLED = OFF SOFT-START VBATT > 2.8V FAST CHARGE (THERMALLY PROTECTED) 100% SETI CURRENT ACOK = LOW RLED = ON GLED = OFF ICHG < ITOP-OFF TOP OFF (VOLTAGE LOOP) RLED = OFF GLED = ON Figure 3. MAX1501Z Charge State Diagram Detailed Description Modes of Operation CHGEN and MODE together set the operating modes of the MAX1501. Both inputs possess internal 175k pulldown resistors to GND. Table 1 describes the four operating modes of the MAX1501. 10 Table 1. Modes of Operation CHGEN MODE Li+ Charge Mode 0 0 NiMH/NiCd Charge Mode 0 1 MODE Disable Mode 1 0 No-Battery Mode 1 1 Maxim Integrated MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications Table 2. Battery Regulation Voltage SELV CHARGING MODE GND VL Li+ 4.1V 4.2V NiMH/NiCd 4.5V 4.95V Li+ Charge Mode Connect CHGEN and MODE to GND to place the MAX1501 in Li+ charging mode. The Li+ charger consists of a voltage-control loop, a current-control loop, and a thermal-control loop. Connect SELV to GND to set the Li+ battery voltage to 4.1V. Connect SELV to VL to set the Li+ battery voltage to 4.2V (Table 2). The MAX1501 precharges the Li+ battery with 10% of the user-programmed fast-charge current at the start of a charge cycle. A soft-start algorithm ramps up the charging current (10% steps with 20ms duration per step) to the fast-charge current when the battery voltage reaches 2.8V. The MAX1501 enters constant-voltage mode and decreases the charge current when the BATT voltage reaches the selected regulation voltage (4.1V or 4.2V). Set the fast-charge current with a resistor between SETI and GND (see the Charge-Current Selection section). REGULATION VOLTAGE PREQUALIFICATION The thermal-regulation loop limits the MAX1501 die temperature to the value selected by the TEMP input by reducing the charge current as necessary (see the Thermal-Regulation Selection section). This feature not only protects the MAX1501 from overheating, but also allows the charge current to be set higher without risking damage to the system. Set the top-off-current threshold with the three-state FULLI input (see the Top-Off-Current Selection section). RLED goes high impedance and GLED asserts low when the top-off-current threshold is reached. The MAX1501 automatically initiates recharging when the battery voltage drops below 95% of the voltage set by SELV. (The MAX1501Z does not time out.) NiMH/NiCd Charge Mode Connect MODE to VL to place the MAX1501 in NiMH/NiCd charging mode. NiMH/NiCd mode uses only current- and voltage-control loops, and is intended for trickle- or timer-based chargers. Fast charge termination schemes, such as negative V or T, are not included in the MAX1501 but can be implemented using an external microcontroller. Trickle- or timer-based chargers should connect SELV to GND to set the regulation voltage to 4.5V. P controlled chargers should connect SELV to VL FAST CHARGING TOP-OFF DONE FAST-CHARGE CURRENT BATTERY CURRENT RLED TURNS OFF AND GLED TURNS ON WHEN CHARGE CURRENT DROPS TO VALUE SET BY FULLI (10%, 20%, OR 30% OF FASTCHARGE CURRENT). BATTERY VOLTAGE MINIMUM CHARGE VOLTAGE (2.8V) CHARGE TERMINATED MAX1501Z 10% OF FAST-CHARGE CURRENT tPREQUAL tMAX MAX1501 Figure 4. Li+ Charge Sequence Maxim Integrated 11 MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications Table 3. RLED and GLED Behavior MODE Li+ Mode or NiMH/NiCd Mode STATE * 10% current-limited precharge * Current-limited charge * Voltage-limited charge before top-off * Temperature-limited charge before top-off * Voltage-limited charge after top-off * Safety timer expires (MAX1501 only) RLED GLED Sinks 10mA High impedance High impedance Sinks 20mA Disable Mode -- High impedance High impedance No Battery Mode -- High impedance High impedance to set the regulation voltage to 4.95V to not interfere with P charge control. When the regulation voltage is 4.95V, VIN must be 5.25V. The MAX1501 precharges with 10% of the user-programmed charge current at the start of a charge cycle. Fast charge begins when VBATT exceeds 2.8V. A resistor from SETI to GND sets charge current. See the Charge-Current Selection section. The MAX1501 enters voltage mode and decreases charge current when VBATT reaches 4.5V. The thermal-regulation loop limits die temperature to the value selected by TEMP by reducing charge current. See the Thermal-Regulation Selection section. This protects the MAX1501 from overheating when supplying high charge currents, or operating from high input voltages. Set the top-off-current threshold with the three-state FULLI input. See the Top-Off-Current Selection section. RLED goes high impedance and GLED asserts low when the top-off current threshold is reached. The MAX1501 automatically initiates recharging when the battery voltage drops below 4V. The MAX1501Z does not time out. No-Battery Mode Connect CHGEN and MODE to VL to place the MAX1501 in no-battery mode. An external load can be connected to BATT in this mode. VBATT regulates to 4V in no-battery mode, regardless of the state of SELV. The current-control loop, voltage-control loop, and thermal-control loop all function in no-battery mode. The loop gain of the voltage-control loop decreases to ensure stability with no battery present. Connect a 10F ceramic capacitor to BATT for stability. RLED and GLED are both high impedance in no-battery mode. ACOK The ACOK output asserts low when VIN is present, 4.2V VIN 6.25V, and VIN - VBATT > 100mV. The ACOK open-drain output requires an external 100k pullup 12 resistor to an external supply voltage. The external supply voltage must be less than 5.5V. RLED and GLED Indicators RLED and GLED serve as visual indicators that power is applied as well as the charge status of a battery. RLED asserts low when a wall adapter is connected and a battery is charging, regardless of cell chemistry. GLED asserts low when power is applied and the battery is fully charged. Both outputs go high-impedance in shutdown. Connect the anode of each LED to IN, and the cathode to RLED or GLED. Table 3 summarizes the behavior of RLED and GLED under normal operating conditions. Connect pullup resistors to the P I/O supply when interfacing RLED and GLED with a P's logic inputs. Soft-Start A ten-step, soft-start algorithm activates when entering fast-charge mode. The charging current ramps up in 10% increments, 20ms per step, to the full charging current when VBATT exceeds 2.8V. Applications Information Charge-Current Selection Program the charging current using an external resistor between SETI and GND. Set the charge-current resistor with the following equation: RSETI = 1000 x 1.4V IBATT If VSETI = 1.4V, the current-control loop controls the battery charging. If VSETI < 1.4V, either the voltagecontrol loop or the thermal-control loop operates. Measure the charging current by monitoring VSETI and using the following equation: I VSETI = BATT x RSETI 1000 Maxim Integrated MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications Thermal-Regulation Selection Set the regulated die temperature of the MAX1501 with the TEMP three-level logic input. The MAX1501 reduces the charge current to limit the die temperature to the value set by TEMP. The MAX1501 operates normally while the thermal loop is active. An active thermal loop does not indicate a fault condition. TEMP allows the MAX1501 to maximize the charge current while providing protection against excessive power dissipation. Connect TEMP to GND to regulate the die temperature at +95C. Leave TEMP floating to regulate the die temperature at +115C. Connect TEMP to VL to regulate the die temperature at +135C. Top-Off-Current Selection Set the top-off-current threshold in the Li+ and NiMH/NiCd charge modes with the FULLI three-level logic input. The top-off-current threshold determines when RLED turns off and GLED turns on, indicating the charge status of the battery. Connect FULLI to GND to set the top-off-current threshold to 10% of the fast-charge current. Connect FULLI to VL to set the top-off-current threshold to 20% of the fast-charge current. Leave FULLI floating to set the topoff-current threshold to 30% of the fast-charge current. Charge-Timer Selection (MAX1501 Only) Set the maximum charging time with the TMAX threelevel logic input. TMAX limits the duration of charging to protect the battery from overcharging. Connect TMAX to GND to set the maximum charging time to 3 hours. Leave TMAX floating to set the maximum charging time AC ADAPTER 4.5V TO 6.5V Capacitor Selection Connect a ceramic capacitor from BATT to GND for proper stability. Use a 10F X5R ceramic capacitor for most applications. Connect IN and INP together and bypass to GND with a 1F ceramic capacitor. Use a larger input bypass capacitor for high input voltages or high charging currents to reduce supply noise. Thermal Considerations The MAX1501 is available in a thermally enhanced thin QFN package with exposed paddle. Connect the exposed paddle of the MAX1501 to a large copper ground plane to provide a thermal contact between the device and the circuit board. The exposed paddle transfers heat away from the device, allowing the MAX1501 to charge the battery with maximum current, while minimizing the increase in die temperature. Application Circuits Figure 5 shows the MAX1501 as a stand-alone Li+ battery charger. The 2.8k resistor connected to SETI sets a charging current of 500mA. Figure 6 shows the MAX1501 as a P-based Li+ battery charger. Drive CHGEN low to charge the battery. Drive CHGEN high to disable the charger. Connect a 100k pullup resistor from ACOK to the logic supply voltage of the P to detect the presence of an input supply. The logic supply voltage must be less than 5.5V. 4.2V 1-CELL Li+ IN 1F to 4.5 hours. Connect TMAX to VL to set the maximum charging time to 6 hours. BATT 10F INP AC ADAPTER 4.5V TO 6.5V 4.2V 1-CELL Li+ IN 1F BATT 10F INP MAX1501/MAX1501Z MAX1501/MAX1501Z GLED MODE RLED CHGEN GLED TMAX/I.C. VI/O ACOK VL TEMP SELV FULLI ACOK P VL CHGEN SELV SETI SETI GND GND Figure 5. Stand-Alone Li+ Battery Charger Maxim Integrated TEMP RPULLUP FULLI 2.8k TMAX/I.C. RLED 2.8k MODE GND GND Figure 6. P-Based Li+ Battery Charger 13 MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications AC ADAPTER 4.5V 3-CELL NiMH OR NiCd 4.75V TO 6.5V IN 1F BATT 10F INP AC ADAPTER IN 1F TEMP RLED ACOK TMAX/I.C. FULLI SETI SELV GLED TMAX/I.C. RLED VI/O TEMP RPULLUP FULLI ACOK P VL CHGEN MODE CHGEN GND 10F MAX1501/MAX1501Z VL 2.8k BATT INP MAX1501/MAX1501Z GLED 4.95V 3-CELL NiMH OR NiCd 5.25V TO 6.5V SELV MODE SETI GND 2.8k GND GND Figure 7. Stand-Alone 3-Cell NiMH or NiCd Battery Charger Figure 8. P-Based NiMH or NiCd Battery Charge Figure 7 shows the MAX1501 as a stand-alone trickle or timer-based NiMH/NiCd battery charger. Connecting SELV to GND sets the charge termination voltage to 4.5V. Figure 8 shows the MAX1501 as a P-based NiMH/NiCd battery charger. Connecting SELV to VL sets the charge regulation voltage at 4.95V. Connect a 100k pullup resistor from ACOK to the logic supply voltage of the P. The logic supply voltage must be less than 5.5V. Figure 9 shows the MAX1501 as a P-based single Li+ or 3-cell NiMH/NiCd charger. The states of MODE and CHGEN set the operating mode of the MAX1501 (Table 1). Connect a 100k pullup resistor from ACOK to the logic supply voltage of the P. The logic supply voltage must be less than 5.5V. Figure 10 shows the MAX1501 as an accurate currentlimited low-dropout linear regulator with input overvoltage protection (no-battery mode). The output voltage regulates to 4V, regardless of the state of SELV. Connect MODE to VL to enable the linear regulator. Connect MODE to GND to put the device into shutdown. RSETI sets the maximum output current. AC ADAPTER 4.1V 1-CELL Li+ OR 4.5V 3-CELL NiMH/NiCd 4.75V TO 6.5V IN 1F BATT 10F INP 4.5V TO 6.5V MAX1501/MAX1501Z 1F 4V IN BATT INP GLED GLED RLED RLED VI/O MAX1501/MAX1501Z 100k FULLI TMAX/I.C. CHGEN 2.8k VL VL ACOK P 10F MODE SELV SETI TEMP GND GND FULLI CHGEN TEMP MODE ON OFF TMAX/I.C. ACOK SELV SETI CURRENT-LIMIT ADJUST GND GND UP TO 1.4A Figure 9. P-Based Single Li+/3-Cell NiMH/NiCd Battery Charger 14 Figure 10. Input Overvoltage-Protected and Current-Limited Low-Dropout Linear Regulator Maxim Integrated MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications 5V 3k 4.1k 5.1k 200k 3k IN 100k MAX1501/MAX1501Z CHGEN 1k 5V 2.24k GND 3k 100k RT = 10k AT +25C 10k 3.66k 1k TBATT RT 0C 27.28k +25C +50C 10.00k 4.16k Figure 11. Battery Temperature Protection INP 1 IN 2 GND 3 SETI 4 GLED RLED SELV GND Pin Configuration Figure 11 shows a circuit that adds temperature protection to the battery. Install the thermistor as close to the battery as possible to ensure accurate temperature measurement. The output of this circuit is logic high when the battery temperature is less than 0C and greater than +50C. Driving CHGEN high disables the charger. 16 15 14 13 12 BATT Layout and Bypassing Chip Information 11 ACOK MAX1501/ MAX1501Z 10 CHGEN **EXPOSED PADDLE 9 7 8 TEMP 6 FULLI VL 5 TMAX/I.C. Connect IN and INP together as close to the device as possible and bypass with a 1F ceramic capacitor. Bypass BATT to GND with a 10F ceramic capacitor. Provide a large copper GND plane to allow the exposed paddle to sink heat away from the device. Connect the battery to BATT as close to the device as possible to provide the most accurate battery voltage sensing. Make all high-current traces short and wide to minimize voltage drops. MODE 5mm x 5mm THIN QFN **CONNECT EXPOSED PADDLE TO GND TRANSISTOR COUNT: 5717 PROCESS: BiCMOS Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Maxim Integrated PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 16 TQFN T1655+3 21-0140 90-0073 15 MAX1501 Highly Integrated, Linear Battery Charger with Thermal Regulation for Portable Applications Revision History REVISION NUMBER REVISION DATE 2 4/14 DESCRIPTION Updated General Description, NiMH/NiCd Charge Mode, and Application Circuits sections PAGES CHANGED 1, 11, 12, 14, 16 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 16 ________________________________Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 (c) 2014 Maxim Integrated Products, Inc. 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