MCP73837/8 Advanced Stand-Alone Li-Ion/Li-Polymer Battery Charge Management Controller with Autonomous AC Adapter or USB Port Source Selection Features Applications • Highly Accurate Preset Voltage Regulation: ±0.5% • Available Voltage Regulation Options: - 4.20V, 4.35V, 4.4V or 4.5V • Complete Linear Charge Management Controller: - Autonomous Power Source Selection - Integrated Pass Transistors - Integrated Current Sense - Integrated Reverse Discharge Protection • Constant Current (CC)/Constant Voltage (CV) Operation with Thermal Regulation • Selectable USB Port Charge Current: - Low: 1 Unit Load - High: 5 Unit Loads • Programmable AC Adapter Charge Current: - 15 mA – 1000 mA • Two-Charge Status Outputs • Power-Good Monitor: MCP73837 • Timer Enable: MCP73838 • Automatic Recharge: - Selectable Voltage Threshold • Automatic End-of-Charge Control: - Selectable Charge Termination Current Ratio - Selectable Safety Timer Period • Preconditioning of Deeply Depleted Cells – Can Be Disabled • Battery Cell Temperature Monitor • UVLO (Undervoltage Lockout) • Automatic Power-Down When Input Power Is Removed • Low-Dropout (LDO) Linear Regulator Mode • Numerous Selectable Options Available for a Variety of Applications: - Refer to Section 1.0 “Electrical Characteristics” for Selectable Options - Refer to the “Product Identification System” for Standard Options • Temperature Range: -40°C to 85°C • Packaging: - 10-Lead 3 mm x 3 mm DFN - 10-Lead MSOP* * Consult the factory for MSOP availability. • Smart Phones and Personal Data Assistants (PDA) • Portable Media Players (PMP) • Ultra Mobile Devices (UMD) • Digital Cameras • MP3 Players • Bluetooth Headsets • Handheld Medical Devices • AC/USB Dual Source Li-Ion Battery Chargers 2007-2015 Microchip Technology Inc. Description The MCP73837 and MCP73838 devices are fully integrated linear Li-Ion/Li-Polymer battery chargers with autonomous power source selection. Along with its small physical size, the low number of external components required makes the MCP73837/8 ideally suitable for portable applications. The MCP73837/8 automatically selects the USB port or AC adapter as the power source for the system. For the USB port powered systems, the MCP73837/8 specifically adheres to the current limits governed by the USB specification. The host microcontroller can select from two preset maximum charge current rates of 100 mA (low-power USB port) or 500 mA (high-power USB port). With an AC adapter providing power to the system, an external resistor sets the magnitude of the system or charge current up to a maximum of 1A. The MCP73837/8 employs a constant current/constant voltage charge algorithm with selectable preconditioning and charge termination. The constant voltage regulation is fixed with four available options: 4.20V, 4.35V, 4.40V or 4.50V, to accommodate the new emerging battery charging requirements. The MCP73837/8 limits the charge current, based on die temperature, during high power or high ambient conditions. This thermal regulation optimizes the charge cycle time while maintaining the reliability of the device . The MCP73837/8 are fully specified over the ambient temperature range of -40°C to +85°C. The MCP73837/8 devices are available in either a 3 mm x 3 mm 10-lead DFN package or a 10-lead MSOP package. DS20002071C-page 1 MCP73837/8 Package Types MCP73837/8 10-Lead MSOP MCP73837/8 3 x 3 10-Lead DFN* VAC VAC 10 VBAT 1 10 VBAT 1 9 THERM VUSB 2 9 THERM 8 PG (TE) STAT1 3 8 PG (TE) STAT2 4 7 PROG2 STAT2 4 7 PROG2 VSS 5 6 PROG1 VUSB 2 EP 11 STAT1 3 VSS 5 6 PROG1 *Includes Exposed Thermal Pad (EP); see Table 3-1. Typical Applications MCP73837 Typical Application 1 AC/DC Adapter 4.7 µF 2 USB Port 4.7 µF 1 k 1 k 1 k 3 4 8 VAC VBAT VUSB THERM STAT1 VSS STAT2 PROG2 PG PROG1 10 Thermistor 9 4.7 µF Single Li-Ion Cell 5 7 Low Hi 6 RPROG MCP73838 Typical Application 1 AC/DC Adapter 4.7 µF 2 USB Port 4.7 µF 1 K 1 K 3 4 5 VAC VBAT VUSB THERM STAT1 STAT2 VSS TE PROG2 PROG1 10 Thermistor 9 4.7 µF Cell 8 Low 7 Hi Low Hi 6 RPROG DS20002071C-page 2 2007-2015 Microchip Technology Inc. MCP73837/8 Functional Block Diagram (MCP73837/8) VOREG Direction Control ȝ$ VUSB VBAT SENSEFET G = 0.001 100mA/500mA 10k 2k SENSEFET G = 0.001 VOREG Direction Control VAC AC/USB + SENSEFET G = 0.001 1k VREF Current Limit - SENSEFET G = 0.001 PROG1 AC/USB Reference, Bias, UVLO, and SHDN VOREG + VREF (1.21V) CA 310k 111k 10k + UVLO - 72.7k - Precondition 470.6k + 48k TERM - PROG2 + CHARGE STAT1 STAT2 Charge Control, Timer, and Status Logic 6k + VA - 157.3k VOREG + LDO PG (TE) 175k + HTVT - ȝ$ 470.6k THERM + LTVT - 175k 121k 2007-2015 Microchip Technology Inc. 1M Vss DS20002071C-page 3 MCP73837/8 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings† VDDN.................................................................................7.0V All Inputs and Outputs w.r.t. VSS ............. -0.3 to (VDD + 0.3)V Maximum Junction Temperature, TJ ............Internally Limited Storage temperature .....................................-65°C to +150°C ESD protection on all pins Human Body Model (1.5 k in Series with 100 pF) ...... ≥4 kV Machine Model (200 pF, No Series Resistance) .............300V † Notice: Stresses above those listed under “Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. DC CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, all limits apply for VDD= [VREG(typical) + 0.3V] to 6V, TA = -40°C to +85°C. Typical values are at +25°C, VDD = [VREG (typical) + 1.0V]. Parameters Sym. Min. Typ. Max. Units Conditions Supply Voltage VDD VREG(Typ) +0.3V — 6 V Supply Current ISS — 1900 3000 µA Charging — — 110 300 µA Charge Complete, No Battery Supply Input (1) 75 100 µA Standby (PROG Floating) 0.6 5 µA Shutdown (VDD ≤ VBAT – 100 mV or VDD < VSTOP) UVLO Start Threshold VSTART 3.35 3.45 3.55 V VDD = Low to High (USB Port) UVLO Stop Threshold VSTOP 3.25 3.35 3.45 V VDD = High to Low (USB Port) VHYS — 75 — mV UVLO Start Threshold VSTART 4.1 4.15 4.3 V (AC Adapter) UVLO Stop Threshold VSTOP 4.0 4.1 4.2 V (AC Adapter) UVLO Hysteresis VHYS — 55 — mV (AC Adapter) VREG 4.179 4.20 4.221 V — 4.328 4.35 4.372 V IOUT = 30 mA 4.378 4.40 4.422 V TA = -5°C to +55°C UVLO Hysteresis (USB Port) Voltage Regulation (Constant Voltage Mode) Regulated Charge Voltage VDD = [VREG(typical) + 1V] 4.477 4.50 4.523 V VRTOL -0.5 — +0.5 % Line Regulation VBAT/VBAT) /VDD| — 0.075 0.2 %/V Load Regulation VBAT/VBAT| — 0.150 0.3 % IOUT = 10 mA to 100 mA VDD = [VREG(typical)+1V] PSRR — 60 — dB IOUT = 10 mA, 10Hz to 1 kHz — — 52 — dB IOUT = 10 mA, 10Hz to 10 kHz — 23 — dB IOUT = 10 mA, 10Hz to 1 MHz Regulated Charge Voltage Tolerance Supply Ripple Attenuation TA = -5°C to +55°C VDD = [VREG(typical)+1V] to 6V IOUT = 30 mA Current Regulation (Fast Charge Constant-Current Mode) AC Adapter Fast Charge Current IREG 95 105 115 mA PROG1 = 10 k — 900 1000 1100 mA PROG1 = 1 k(2) TA = -5°C to +55°C The supply voltage (VDD) = VAC when input power source is from AC adapter and the supply voltage (VDD) = VUSB when input power source is from the USB port. 2: The value is guaranteed by design and not production tested. 3: The current is based on the ratio of selected current regulation (IREG). The maximum charge impedance has to be less than shutdown impedance for normal operation. Note 1: DS20002071C-page 4 2007-2015 Microchip Technology Inc. MCP73837/8 DC CHARACTERISTICS (Continued) Electrical Specifications: Unless otherwise indicated, all limits apply for VDD= [VREG(typical) + 0.3V] to 6V, TA = -40°C to +85°C. Typical values are at +25°C, VDD = [VREG (typical) + 1.0V]. Parameters USB port Fast Charge Current Maximum Output Current Limit Sym. Min. Typ. Max. Units IREG 80 90 100 mA PROG2 = Low Conditions — 400 450 500 mA PROG2 = High TA = -5°C to +55°C IMAX — 1200 — mA PROG1 < 833 12.5 % (3) TA = -5°C to +55°C Precondition Current Regulation (Trickle Charge Constant-Current Mode) Precondition Current Ratio IPREG/IREG — Precondition Current Threshold Ratio 7.5 10 15 20 25 % 30 40 50 % — 100 — % VPTH/VREG 64 66.5 69 % VBAT Low to High — 69 71.5 74 % VPHYS — 120 — mV ITERM/IREG 3.75 5 6.25 % PROG1 = 1 kto 10 k — 5.6 7.5 9.4 % TA = -5°C to +55°C 7.5 10 12.5 % (3) 15 20 25 % VRTH/VREG 92 94.0 96 % VBAT High to Low — 95 97 99 % TA = -5°C to +55°C RDSON — 350 — m VDD = 4.5V, TJ = +105°C IDISCHARGE — 0.1 2 µA Standby (PROG1 or PROG2 Floating) — — 0.55 2 µA Shutdown (VDD ≤ VBAT -100 mV or VDD < VSTOP) — -6 -15 µA Charge Complete mA Precondition Hysteresis VBAT High to Low Charge Termination Charge Termination Current Ratio Automatic Recharge Recharge Voltage Threshold Ratio Pass Transistor ON-Resistance ON-Resistance Battery Discharge Current Output Reverse Leakage Current Status Indicators – STAT1, STAT2, PG (MCP73837) Sink Current ISINK — 16 35 Low Output Voltage VOL — 0.3 1 V ISINK = 4 mA Input Leakage Current ILK — 0.03 1 µA High Impedance, VDD on pin Charge Impedance Range RPROG 1 — — k (4) Shutdown Impedance RPROG 70 — 200 k Minimum Impedance for Shutdown Input High Voltage Level VIH 0.8VDD — — % Input Low Voltage Level VIL — — 0.2VDD % Shutdown Voltage Level VSD 0.2VDD — 0.8VDD % Input Leakage Current ILK — 7 15 µA PROG1 Input (PROG1) PROG2 Inputs (PROG2) VPROG2 = VDD The supply voltage (VDD) = VAC when input power source is from AC adapter and the supply voltage (VDD) = VUSB when input power source is from the USB port. 2: The value is guaranteed by design and not production tested. 3: The current is based on the ratio of selected current regulation (IREG). The maximum charge impedance has to be less than shutdown impedance for normal operation. Note 1: 2007-2015 Microchip Technology Inc. DS20002071C-page 5 MCP73837/8 DC CHARACTERISTICS (Continued) Electrical Specifications: Unless otherwise indicated, all limits apply for VDD= [VREG(typical) + 0.3V] to 6V, TA = -40°C to +85°C. Typical values are at +25°C, VDD = [VREG (typical) + 1.0V]. Parameters Sym. Min. Typ. Max. Units Conditions VIH 2 — — V Input Low Voltage Level VIL — — 0.8 V Input Leakage Current ILK — 0.01 1 µA VTE = VDD ITHERM 47 50 53 µA 2 k < RTHERM < 50 k VT1 1.20 1.23 1.26 V VT1 Low to High Timer Enable (TE) Input High Voltage Level Thermistor Bias Thermistor Current Source Thermistor Comparator Upper Trip Threshold Upper Trip Point Hysteresis VT1HYS — -40 — mV VT2 0.235 0.250 0.265 V VT2HYS — 40 — mV VIH — — VDD – 0.1 V THERM Input Sink Current ISINK 3 5.5 20 µA Stand-by or System Test Mode Bypass Capacitance CBAT 1 4.7 — — µF µF IOUT < 250 mA IOUT > 250 mA Lower Trip Threshold Lower Trip Point Hysteresis VT2 High to Low System Test (LDO) Mode Input High Voltage Level Automatic Power Down (SLEEP Comparator, Direction Control) Automatic Power Down Entry Threshold Automatic Power Down Exit Threshold VPD VBAT + 10 mV VBAT + 100 mV — V 2.3V ≤ VBAT ≤ VREG VDD Falling VPDEXIT — VBAT + 150 mV VBAT + 250 mV V 2.3V ≤ VBAT ≤ VREG VDD Rising TSD — 150 — C TSDHYS — 10 — C Thermal Shutdown Die Temperature Die Temperature Hysteresis Note 1: The supply voltage (VDD) = VAC when input power source is from AC adapter and the supply voltage (VDD) = VUSB when input power source is from the USB port. 2: The value is guaranteed by design and not production tested. 3: The current is based on the ratio of selected current regulation (IREG). The maximum charge impedance has to be less than shutdown impedance for normal operation. DS20002071C-page 6 2007-2015 Microchip Technology Inc. MCP73837/8 AC CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, all limits apply for VDD = [VREG (typical) + 0.3V] to 6V. Typical values are at +25°C, VDD = [VREG (typical) + 1.0V] . Parameters Sym. Min. Typ. Max. Units tSTART — — 5 ms VDD Low to High tDELAY — — 10 ms VBAT < VPTH to VBAT > VPTH tRISE — — 10 ms IOUT Rising to 90% of IREG Precondition Comparator Filter Time tPRECON 0.4 1.3 3.2 ms Average VBAT Rise/Fall Termination Comparator Filter Time tTERM 0.4 1.3 3.2 ms Average IOUT Falling Charge Comparator Filter Time tCHARGE 0.4 1.3 3.2 ms Average VBAT Falling Thermistor Comparator Filter Time tTHERM 0.4 1.3 3.2 ms Average THERM Rise/Fall tELAPSED 0 0 0 Hours — 3.6 4.0 4.4 Hours — 5.4 6.0 6.6 Hours — 7.2 8.0 8.8 Hours Status Output Turn-off tOFF — — 500 µs ISINK = 1 mA to 0 mA Status Output Turn-on tON — — 500 µs ISINK = 0 mA to 1 mA UVLO Start Delay Conditions Current Regulation Transition Time Out of Precondition Current Rise Time Out of Precondition Elapsed Timer Elapsed Timer Period Timer Disabled Status Indicators TEMPERATURE SPECIFICATIONS Electrical Specifications: Unless otherwise indicated, all limits apply for VDD = [VREG (typ.) + 0.3V] to 6V. Typical values are at +25°C, VDD = [VREG (typ.) + 1.0V] . Parameters Sym. Min. Typ. Max. Units Conditions Specified Temperature Range TA -40 — +85 °C Operating Temperature Range TJ -40 — +125 °C Storage Temperature Range TA -65 — +150 °C Thermal Resistance, 10-Lead MSOP JA — 113 — °C/W 4-Layer JC51-7 Standard Board, Natural Convection(1) Thermal Resistance, 10-Lead 3 x 3 DFN JA — 41 — °C/W 4-Layer JC51-7 Standard Board, Natural Convection Temperature Ranges Thermal Package Resistances Note 1: This represents the minimum copper condition on the Printed Circuit Board (PCB). 2007-2015 Microchip Technology Inc. DS20002071C-page 7 MCP73837/8 2.0 TYPICAL PERFORMANCE CURVES Note: The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore outside the warranted range. TEMP = 25°C IOUT = 50 mA IOUT = 10 mA IOUT = 100 mA IOUT = 500 mA IOUT = 1000 mA 4.5 4.8 5.0 5.3 5.5 Supply Voltage (V) 5.8 Battery Regulation Voltage (V) 4.205 IOUT = 10 mA VDD = 5.2V IOUT = 50 mA 4.200 4.195 IOUT = 100 mA 4.190 IOUT = 500 mA 4.185 4.180 IOUT = 1000 mA 4.175 4.170 Battery Voltage (V) FIGURE 2-3: Output Leakage Current (IDISCHARGE) vs. Battery Regulation Voltage (VBAT). DS20002071C-page 8 1.2 0.8 0.4 0.0 10 20 30 40 50 60 70 80 Temperature (°C) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 VDD = Floating TEMP = +25°C Battery Voltage (V) FIGURE 2-5: Output Leakage Current (IDISCHARGE) vs. Battery Voltage (VBAT). VDD = VBAT TEMP = 25 °C 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 1.6 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 IREG (mA) Output Leakage Current (µA) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 VDD = Floating VBAT = 4.2V FIGURE 2-4: Output Leakage Current (IDISCHARGE) vs. Ambient Temperature (TA). -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Ambient Temperature (°C) FIGURE 2-2: Battery Regulation Voltage (VBAT) vs. Ambient Temperature (TA). 2.0 -40 -30 -20 -10 0 6.0 FIGURE 2-1: Battery Regulation Voltage (VBAT) vs. Supply Voltage (VDD). 4.210 Output Leakage Current (µA) 4.210 4.205 4.200 4.195 4.190 4.185 4.180 4.175 4.170 4.165 4.160 Output Leakage Current (µA) Battery Regulation Voltage (V) Note: Unless otherwise indicated, VDD = [VREG(typical) + 1V], IOUT = 30 mA, and TA= +25°C, Constant-voltage mode. 1000 900 800 700 600 500 400 300 200 100 0 VDD = 5.2V Temp = 25°C 1 6 11 16 21 26 31 36 41 46 51 56 61 RPROG (kΩ) FIGURE 2-6: Charge Current (IOUT) vs. Programming Resistor (RPROG). 2007-2015 Microchip Technology Inc. MCP73837/8 1200 1150 1100 1050 1000 950 900 850 800 750 700 RPROG = 1 kΩ Temp = +25°C 4.5 4.8 5.0 5.3 5.5 Supply Voltage (V) 5.8 100 98 96 94 92 RPROG = 10 kΩ VDD = 5.2V -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Ambient Temperature (°C) FIGURE 2-10: Charge Current (IOUT) vs. Ambient Temperature (TA). Charge Current (mA) Charge Current (mA) RPROG = 10 kΩ Temp = +25°C 102 110 108 106 104 102 100 98 96 94 92 90 6.0 FIGURE 2-7: Charge Current (IOUT) vs. Supply Voltage (VDD). 104 Charge Current (mA) Charge Current (mA) Note: Unless otherwise indicated, VDD = [VREG(typical) + 1V], IOUT = 30 mA and TA= +25°C, Constant-voltage mode. 90 55 54 53 52 51 50 49 48 47 46 45 RPROG = 20 kΩ VDD = 5.2V -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Ambient Temperature (°C) FIGURE 2-8: Charge Current (IOUT) vs. Supply Voltage (VDD). FIGURE 2-11: Charge Current (IOUT) vs. Ambient Temperature (TA). Ambient Temperature (°C) FIGURE 2-9: Charge Current (IOUT) vs. Ambient Temperature (TA). 2007-2015 Microchip Technology Inc. 155 145 135 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 125 700 115 750 105 800 95 850 85 900 75 950 RPROG = 1 kΩ 65 Charge Current (mA) 1000 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 55 RPROG = 1 kΩ VDD = 5.2V 1050 45 1100 5.8 35 5.0 5.3 5.5 Supply Voltage (V) 25 4.8 Charge Current (mA) 6.0 4.5 Junction Temperature (°C) FIGURE 2-12: Charge Current (IOUT) vs. Junction Temperature (TJ). DS20002071C-page 9 MCP73837/8 52.0 51.5 51.0 50.5 50.0 49.5 49.0 48.5 48.0 47.5 47.0 90 80 70 60 50 40 30 20 0 FIGURE 2-16: Thermistor Current (ITHERM) vs. Ambient Temperature (TA). 0 RPROG = 10 kΩ Attenuation (dB) -10 IOUT = 10 mA COUT = 4.7 µF -20 -30 -40 -50 -70 0.01 155 145 135 125 115 105 95 85 75 65 55 45 35 25 -60 0.1 1 FIGURE 2-14: Charge Current (IOUT) vs. Junction Temperature (TJ). 52.0 51.5 51.0 50.5 50.0 49.5 49.0 48.5 48.0 47.5 47.0 10 100 1000 Frequency (kHz) Junction Temperature (°C) FIGURE 2-17: Power Supply Ripple Rejection (PSRR). 0 Temp = +25°C -10 Attenuation (dB) Thermistor Current (mA) 10 -10 Ambient Temperature (°C) FIGURE 2-13: Charge Current (IOUT) vs. Junction Temperature (TJ). Charge Current (mA) -20 Junction Temperature (°C) 120 110 100 90 80 70 60 50 40 30 20 10 0 VDD = 5.2V -30 Thermistor Current (mA) 155 145 135 125 115 95 105 85 75 65 55 45 35 RPROG = 2 kΩ -40 600 550 500 450 400 350 300 250 200 150 100 50 0 25 Charge Current (mA) Note: Unless otherwise indicated, VDD = [VREG(typical) + 1V], IOUT = 30 mA and TA= +25°C, Constant-voltage mode. IOUT = 100 mA COUT = 4.7 µF -20 -30 -40 -50 -60 4.5 4.8 5.0 5.3 5.5 Supply Voltage (V) 5.8 6.0 FIGURE 2-15: Thermistor Current (ITHERM) vs. Supply Voltage (VDD). DS20002071C-page 10 -70 0.01 0.1 1 10 100 1000 Frequency (kHz) FIGURE 2-18: Power Supply Ripple Rejection (PSRR). 2007-2015 Microchip Technology Inc. MCP73837/8 -0.5 700 600 500 400 300 200 100 0 -100 -200 Time (Minutes) Time (µs) FIGURE 2-19: Line Transient Response. FIGURE 2-22: Load Transient Response. 0.1 VOUT 14 0 12 -0.1 10 8 -0.2 VIN 6 -0.3 4 -0.4 2 VIN Output Ripple (V) 16 Input Source (V) 0.1 0.05 0 -0.05 -0.1 -0.15 -0.2 -0.25 -0.3 1.6E-03 0 1.4E-03 IOUT = 100 mA -4.0E-04 -0.4 2 1.2E-03 4 IOUT 1.0E-03 -0.3 8.0E-04 -0.2 VIN 6 6.0E-04 8 4.0E-04 -0.1 10 IOUT = 100 mA VOUT 2.0E-04 12 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -0.1 0.0E+00 0 Output Ripple (V) Input Source (V) 14 Output Current (A) 0.1 VOUT -2.0E-04 16 Output Ripple (V) Note: Unless otherwise indicated, VDD = [VREG(typical) + 1V], IOUT = 30 mA and TA= +25°C, Constant-voltage mode. VOUT IOUT = 10 mA 0 -0.5 800 700 600 500 400 300 200 100 0 -100 -200 Time (µs) 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 -0.05 Line Transient Response. 0.04 0.02 0 -0.02 -0.04 -0.06 -0.08 -0.1 -0.12 IOUT = 10 mA VOUT(AC) IOUT Output Ripple (V) Output Current (A) FIGURE 2-20: FIGURE 2-23: (IOUT = 1A). VAC Start Delay VIN 1.6E-03 1.4E-03 1.2E-03 1.0E-03 8.0E-04 6.0E-04 4.0E-04 2.0E-04 0.0E+00 -2.0E-04 -4.0E-04 VOUT Time (Minutes) FIGURE 2-21: Load Transient Response. 2007-2015 Microchip Technology Inc. FIGURE 2-24: (USB = Low). VUSB Start Delay DS20002071C-page 11 MCP73837/8 Note: Unless otherwise indicated, VDD = [VREG(typical) + 1V], IOUT = 30 mA and TA= +25°C, Constant-voltage mode. UVLOVAC Battery Voltage (V) VOUT 0.12 VOUT 0.1 4.0 0.08 3.0 0.06 IOUT 2.0 0.04 VDD = 5.2V RPROG = USB_Low 180 mAh Li-Ion Battery 1.0 0.02 0.0 Charge Current (A) 5.0 VIN 0 0 20 40 60 80 100 120 140 160 180 Time (Minutes) FIGURE 2-28: Complete Charge Cycle (180 mAh Li-Ion Battery). Battery Voltage (V) VOUT 4.0 1.2 5.0 1 4.0 0.8 3.0 IOUT 0.6 2.0 0.4 VDD = 5.2V RPROG = 1 kΩ 1200 mAh Li-Ion Battery 1.0 0.06 C.V. Begins 2.0 0.04 VDD = 5.2V RPROG = USB_Low 180 mAh Li-Ion Battery 1.0 0.02 0 0 1 2 3 4 5 6 7 8 9 10 Time (Minutes) FIGURE 2-29: Typical Charge Profile in Preconditioning and CC-CV (180 mAh Li-Ion Battery). FIGURE 2-26: Complete Charge Cycle (1200 mAh Li-Ion Battery). 4.5 0.08 3.0 0.0 0 Time (Minutes) 1.2 3.5 0.9 3.0 IOUT 2.5 0.6 2.0 1.5 VDD = 5.2V RPROG = 1 kΩ 1200 mAh Li-Ion Battery 1.0 0.5 0.3 0.0 Charge Current (A) VOUT 4.0 Battery Voltage (V) 0.1 IOUT Preconditioning 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 0.0 0.2 0.12 VOUT C.C. Begins Battery Voltage (V) 5.0 Charge Current (A) VUSB Start Delay Charge Current (A) FIGURE 2-25: (USB = High) 0 0 1 2 3 4 5 6 7 8 9 10 Time (Minutes) FIGURE 2-27: Typical Charge Profile in Thermal Regulation (1200 mAh Li-Ion Battery). DS20002071C-page 12 2007-2015 Microchip Technology Inc. MCP73837/8 3.0 PIN DESCRIPTION The descriptions of the pins are listed in Table 3-1. TABLE 3-1: PIN FUNCTION TABLE Pin Number Symbol I/O Function DFN-10 MSOP-10 1 1 VAC I AC Adapter Supply Input 2 2 VUSB I USB port Supply Input 3 3 STAT1 O Charge Status Output 1 (Open-Drain) 4 4 STAT2 O Charge Status Output 2 (Open-Drain) — Battery Management 0V Reference 3.1 5 5 VSS 6 6 PROG1 7 7 PROG2 I Current Regulation Setting With USB Port; Precondition Set Point for USB control. 8 8 PG O Available on MCP73837: Power-Good Status Output (Open-Drain) 8 8 TE I Available on MCP73838: Timer Enable; Enables Safety Timer (Active Low) 9 9 10 10 VBAT 11 — EP I/O Current Regulation Setting With AC Adapter; Device Charge Control Enable; Precondition Set Point for AC control THERM I/O Thermistor Monitoring Input and Bias current; System Test (LDO) Mode Input I/O Battery Positive Input and Output Connection — EP (Exposed Thermal Pad) There is an internal electrical connection between the exposed thermal pad and VSS. The EP must be connected to the same potential as the VSS pin on the PCB. AC Adapter Supply Input (VAC) A supply voltage of VREG + 0.3V to 6V from the AC/DC wall-adapter is recommended. When both the AC adapter and the USB port supply voltages are present at the same time, the AC adapter dominates the regulated charge current with the maximum value of 1A. Bypass to VSS, with a minimum of 4.7 µF, is recommended. 3.2 USB Port Supply Input (VUSB) A supply voltage of VREG + 0.3V to 6V from the USB port is recommended. When no supply voltage from VAC pin is available, the Li-Ion battery is charged directly from USB port. Bypass to VSS, with a minimum of 1 µF, is recommended. 3.3 Charge Status Output 1 (STAT1) 3.5 Battery Management 0V Reference (VSS) Connect to the negative terminal of the battery and input supply. 3.6 AC Adapter Current Regulation Set (PROG1) The AC adapter constant charge current is set by placing a resistor from PROG1 to VSS. PROG1 is the set point of precondition and termination when the AC adapter is present. PROG1 also functions as device charge control enable. The MCP73837/8 is shut down when an impedance value greater than 70 k is applied to PROG1. When PROG1 is floating, the MCP73837/8 enters into Stand-By mode. STAT1 is an open-drain logic output for connection to a LED for charge status indication. Alternatively, a pull-up resistor can be applied for interfacing to a host microcontroller. 3.4 Charge Status Output 2 (STAT2) STAT2 is an open-drain logic output for connection to a LED for charge status indication. Alternatively, a pull-up resistor can be applied for interfacing to a host microcontroller. 2007-2015 Microchip Technology Inc. DS20002071C-page 13 MCP73837/8 3.7 USB Port Current Regulation Set (PROG2) The MCP73837/8 USB port current regulation set input (PROG2) is a digital input selection. A logic Low selects a 1 unit load charge current; a logic High selects a 5 unit loads charge current. The precondition and termination current is internally set to the percentage levels selected by the device part number. The current is based on the selected unit load charge current, based on the level of PROG2. 3.12 Exposed Thermal Pad (EP) The 10-lead 3 x 3 mm DFN package has an exposed metal pad on the bottom of the package. It gives the device better thermal characteristics by providing a good thermal path to a PCB ground plane.There is an internal electrical connection between the EP and the VSS pin; they must be connected to the same potential on the PCB. PROG2 also functions as the set point of termination when the USB port is present. When PROG2 is floating, the MCP73837/8 enters into Stand-By mode. 3.8 Power Good (PG) Power Good (PG) is available only on MCP73837. PG is an open-drain logic output for connection to an LED for input power supply indication. Alternatively, a pull-up resistor can be applied for interfacing to a host microcontroller. 3.9 Timer Enable (TE) Timer Enable (TE) is available only on MCP73838. TE enables the built-in safety timer when it is pulled Low, and disables the built-in safety timer when it is pulled High. Note: 3.10 The built-in safety timer is available for both MCP73837 and MCP73838 in the following options: Disable, 4 HR, 6 HR, and 8 HR. Battery Temperature Monitor (THERM) MCP73837/8 continuously monitors the battery temperature during a charge cycle by measuring the voltage between the THERM and VSS pins. An internal 50 µA current source provides the bias for the most common 10 k negative-temperature coefficient thermistors (NTC). 3.11 Battery Charge Control Output (VBAT) Connect to the positive terminal of Li-Ion/Li-Polymer batteries. Bypass to VSS, with a minimum of 1 µF, to ensure loop stability when the battery is disconnected. DS20002071C-page 14 2007-2015 Microchip Technology Inc. MCP73837/8 4.0 DEVICE OVERVIEW The MCP73837/8 devices are simple, yet fully integrated, linear charge management controllers. Figure 4-1 depicts the operational flow algorithm. SHUTDOWN MODE* VDD VBAT -100 mV VDD < VSTOP * Continuously Monitored STAT1 = High Z STAT2 = High Z PG = High Z SYSTEM TEST (LDO) MODE VTHERM > (VDD -100 mV) STAT1 = LOW STAT2 = LOW PG = LOW Timer Suspended STANDBY MODE * VDD > (VREG + 100 mV) PROG > 200 k STAT1 = High Z STAT2 = High Z PG = LOW VBAT < VPTH PRECONDITIONING MODE Charge Current = IPREG STAT1 = LOW STAT2 = High Z PG = LOW Timer Reset VBAT > VPTH FAST CHARGE MODE Charge Current = IREG STAT1 = LOW STAT2 = High Z PG = LOW Timer Enabled TEMPERATURE FAULT No Charge Current STAT1 = High Z STAT2 = High Z PG = LOW Timer Suspended VBAT > VPTH Timer Expired VBAT < VRTH TIMER FAULT No Charge Current STAT1 = High Z STAT2 = High Z PG = LOW Timer Suspended VBAT = VREG CONSTANT VOLTAGE MODE Charge Voltage = VREG STAT1 = LOW STAT2 = High Z PG = LOW IBAT < ITERM Timer Expired CHARGE COMPLETE MODE No Charge Current STAT1 = High Z STAT2 = LOW PG = LOW FIGURE 4-1: Operational Algorithm. 2007-2015 Microchip Technology Inc. DS20002071C-page 15 MCP73837/8 4.1 Undervoltage Lockout (UVLO) 4.4 Preconditioning An internal undervoltage lockout (UVLO) circuit monitors the input voltage and keeps the charger in Shutdown mode until the input supply rises above the UVLO threshold. The UVLO circuitry has a built-in hysteresis of 75 mV for the USB port and 55 mV for the AC adapter. If the voltage at the VBAT pin is less than the preconditioning threshold, the MCP73837/8 enters a preconditioning mode. The preconditioning threshold is factory set. In the event a battery is present when the input power is applied, the input supply must rise 100 mV above the battery voltage before MCP73837/8 becomes operational. In this mode, the MCP73837/8 supplies a percentage of the charge current (established with the value of the resistor connected to the PROG1 pin for AC mode, established by PROG2 level for USB mode) to the battery. The percentage or ratio of the current is factory set. Refer to Section 1.0 “Electrical Characteristics” for preconditioning current options. The UVLO circuit places the device in shutdown mode if the input supply falls to within +100 mV of the battery voltage. Refer to Section 1.0 “Electrical Characteristics” for preconditioning threshold options. The UVLO circuit is always active. If, at any time, the input supply is below the UVLO threshold or within +100 mV of the voltage at the VBAT pin, the MCP73837/8 is placed in a Shutdown mode. When the voltage at the VBAT pin rises above the preconditioning threshold, the MCP73837/8 enters the Constant Current or Fast Charge mode. During any UVLO condition, the battery reverse discharge current is less than 2 µA. 4.5 4.2 Autonomous Power Source Selection The MCP73837/8 devices are designed to select the USB port or AC adapter as the power source automatically. If the AC adapter input is not present, the USB port is selected. If both inputs are available, the AC adapter has first priority. Constant Current Mode – Fast Charge During Constant Current mode, the programmed (AC adapter) or selected (USB port) charge current is supplied to the battery or load. For AC adapter, the charge current is established using a single resistor from PROG1 to VSS. The program resistor and the charge current are calculated using the Equation 4-1. EQUATION 4-1: Note: 4.3 If the input power is switched during a charge cycle, the power path switch-over will be a break-before-make connection. As a result, the charge current can momentarily go to zero. The charge cycle timer will remain continuous. Charge Qualification For a charge cycle to begin, all UVLO conditions must be met and a battery or output load must be present. A charge current programming resistor must be connected from PROG1 to VSS. If the PROG1 or PROG2 pin are open or floating, the MCP73837/8 is disabled and the battery reverse discharge current is less than 2 µA. In this manner, the PROG1 pin acts as a charge enable and can be used as a manual shutdown. 1000V I REG = -------------------RPROG Where: RPROG = kilohm (k IREG = milliampere (mA) When charging from a USB port, the host microcontroller has the option of selecting either a one-unit-load or a five-unit-loads charge rate based on the PROG2 input. A logic Low selects a one-unit-load charge rate, a High selects a five-unit-loads charge rate, and high impedance input suspends or disables charging. Note: USB Specification Rev. 2.0 defines the maximum absolute current for one unit load is 100 mA. This value is not an average over time and cannot be exceeded. Constant Current mode is maintained until the voltage at the VBAT pin reaches the regulation voltage, VREG. When constant current mode is invoked, the internal timer is reset. DS20002071C-page 16 2007-2015 Microchip Technology Inc. MCP73837/8 TIMER EXPIRED DURING CONSTANT CURRENT – FAST CHARGE MODE If the internal timer expires before the recharge voltage threshold is reached, a timer fault is indicated and the charge cycle terminates. The MCP73837/8 remains in this condition until the battery is removed, the input battery is removed or the PROG1/2 pin is opened. If the battery is removed or the PROG1/2 pin is opened, the MCP73837/8 enters the Stand-by mode where it remains until a battery is reinserted or the PROG1/2 pin is reconnected. If the input power is removed, the MCP73837/8 is in Shutdown. When the input power is reapplied, a normal start-up sequence begins. 4.6 Constant Voltage Mode When the voltage at the VBAT pin reaches the regulation voltage, VREG, constant voltage regulation begins. The regulation voltage is factory set to 4.20V, 4.35V, 4.40V, or 4.5V, with a tolerance of ± 0.5%. 4.9 Thermal Regulation The MCP73837/8 limits the charge current based on the die temperature. The thermal regulation optimizes the charge cycle time while maintaining device reliability. Figure 4-2 depicts the thermal regulation for the MCP73837/8. Refer to Section 1.0 “Electrical Characteristics” for thermal package resistances and Section 6.1.1.3 “Thermal Considerations” for calculating power dissipation. . 1200 RPROG = 1 kΩ 1100 1000 Charge Current (mA) 4.5.1 900 800 700 600 500 400 300 200 100 0 25 4.7 35 45 Charge Termination The charge cycle is terminated when, during constant voltage mode, the average charge current diminishes below a percentage of the programmed charge current, or the internal timer has expired. A 1 ms filter time on the termination comparator ensures that transient load conditions do not result in premature charge cycle termination. The percentage or ratio of the current is factory set. The timer period is factory set and can be disabled. Refer to Section 1.0 “Electrical Characteristics” for charge termination current ratio and timer period options. FIGURE 4-2: 4.10 55 65 75 85 95 105 115 125 135 145 155 Junction Temperature (°C) Thermal Regulation. Thermal Shutdown The MCP73837/8 suspends charge if the die temperature exceeds +150°C. Charging will resume when the die temperature has cooled by approximately +10°C. The thermal shutdown is a secondary safety feature in the event that there is a failure within the thermal regulation circuitry. The charge current is latched off and the MCP73837/8 enters a charge complete mode. 4.8 Automatic Recharge The MCP73837/8 continuously monitors the voltage at the VBAT pin in the charge complete mode. If the voltage drops below the recharge threshold, another charge cycle begins and current is once again supplied to the battery or load. The recharge threshold is factory set. Refer to Section 1.0 “Electrical Characteristics” for recharge threshold options. Note: Charge termination and automatic recharge features avoid constantly charging a Li-Ion battery in order to prolong its life, while keeping its capacity at a healthy level. 2007-2015 Microchip Technology Inc. DS20002071C-page 17 MCP73837/8 5.0 DETAILED DESCRIPTION • • 5.1 Analog Circuitry Digital Circuitry Analog Circuitry 5.1.1 BATTERY MANAGEMENT INPUT SUPPLY (VDD) The VDD input is the input supply to the MCP73837/8. The MCP73837/8 can be supplied by either AC adapter (VAC) or USB port (VUSB) with autonomous source selection. The MCP73837/8 automatically enters a Power-Down mode if the voltage on the VDD input falls to within +100 mV of the battery voltage or below the UVLO voltage (VSTOP). This feature prevents draining the battery pack when both the VAC and VUSB supplies are not present. 5.1.2 AC ADAPTER CURRENT REGULATION SET (PROG1) For the MCP73837/8, the charge current regulation can be scaled by placing a programming resistor (RPROG) from the PROG1 input to VSS. The program resistor and the charge current are calculated using the following equation: EQUATION 5-1: 1000V I REG = ----------------RPROG Where: RPROG = kilohm (k IREG = milliampere (mA The preconditioning current and the charge termination current are ratiometric to the fast charge current based on the selected device options. 5.1.3 BATTERY CHARGE CONTROL OUTPUT (VBAT) The battery charge control output is the drain terminal of an internal P-channel MOSFET. The MCP73837/8 provides constant current and voltage regulation to the battery pack by controlling this MOSFET in the linear region. The battery charge control output should be connected to the positive terminal of the battery pack. DS20002071C-page 18 5.1.4 TEMPERATURE QUALIFICATION (THERM) The MCP73837/8 continuously monitors battery temperature during a charge cycle by measuring the voltage between the THERM and the VSS pins. An internal 50 µA current source provides the bias for the most common 10 k negative-temperature coefficient (NTC) or positive-temperature coefficient (PTC) thermistors. The current source is controlled, avoiding measurement sensitivity to fluctuations in the supply voltage (VDD). The MCP73837/8 compares the voltage at the THERM pin to factory set thresholds of 1.20V and 0.25V, typically. If a voltage that is outside the thresholds is detected during a charge cycle, the MCP73837/8 immediately suspends the charge cycle. The MCP73837/8 suspends charge by turning off the pass transistor and holding the timer value. The charge cycle resumes when the voltage at the THERM pin returns to the normal range. If temperature monitoring is not required, place a standard 10 k resistor from THERM to VSS. 5.1.5 SYSTEM TEST (LDO) MODE The MCP73837/8 can be placed in a System Test mode. In this mode, the MCP73837/8 operates as a low dropout (LDO) linear regulator. The output voltage is regulated to the factory set voltage regulation option. The available output current is limited to the programmed fast charge current. For stability, the VBAT output must be bypassed to VSS with a minimum capacitance of 1 µF for output currents up to 250 mA. A minimum capacitance of 4.7 µF is required for output currents above 250 mA. The system test mode is entered by driving the THERM input greater than (VDD – 100 mV) with no battery connected to the output. In this mode, the MCP73837/8 can be used to power the system without a battery being present. Note 1: ITHERM is disabled during shutdown, stand-by, and system test modes. 2: A pull-down current source on the THERM input is active only in Stand-By and System Test modes. 3: During System Test mode, the PROG input sets the available output current limit. 4: System Test mode shall be exited by releasing the THERM input or cycling input power. 2007-2015 Microchip Technology Inc. MCP73837/8 5.2 Digital Circuitry 5.2.1 5.2.4 STATUS INDICATORS AND POWER GOOD (PG) OPTION The charge status outputs have two different states: Low (L), and High Impedance (Hi-Z). The charge status outputs can be used to illuminate LEDs. Optionally, the charge status outputs can be used as an interface to a host microcontroller. Table 5-1 summarizes the state of the status outputs during a charge cycle. 5.2.2 USB PORT CURRENT REGULATION SELECT (PROG2) For the MCP73837/8, driving the PROG2 input to a logic Low selects the low charge current setting (maximum 100 mA). Driving the PROG2 input to a logic High selects the high charge current setting (maximum 500 mA). The Precondition current and Termination current are percentages of the charge current selected by the PROG2 level. The percentage is based on the selected part number of the device. TABLE 5-1: Charge Cycle State STAT1 STAT2 PG High Z High Z High-Z Standby L High-Z High Z Preconditioning L High Z L Constant Current L High Z L Constant Voltage L High Z L L Charge Complete – Standby High Z L Temperature Fault High Z High Z L Timer Fault High Z High Z L L L L 5.2.3 The timer enable (TE) input option is used to enable or disable the internal timer. It is only available on the MCP73838. A low signal on this pin enables the internal timer and a high signal disables the internal timer. The TE input can be used to disable the timer when the charger is supplying current to charge the battery and power the system load. The TE input is compatible with 1.8V logic. 5.2.5 DEVICE DISABLE (PROG1/2) The current regulation set input pin (PROG1/2) can be used to terminate a charge at any time during the charge cycle, as well as to initiate a charge cycle or to initiate a recharge cycle. Placing a programming resistor from the PROG1/2 input to VSS enables the device. Allowing the PROG1/2 input to float or applying a logic-high input signal to PROG1 disables the device and terminates a charge cycle. When disabled, the device’s supply current is reduced to 75 µA, typically. STATUS OUTPUTS Shutdown System Test Mode TIMER ENABLE (TE) OPTION POWER GOOD (PG) OPTION The power good (PG) option is a pseudo open-drain output. It is only available on the MCP73837. The PG output can sink current, but not source current. However, there is a diode path back to the input, and as such, the output should be pulled up only to the input. The PG output is low whenever the input to the MCP73837 is above the UVLO threshold and greater than the battery voltage. If the supply voltage is above the UVLO, but below VREG(typical)+0.3V, the MCP73837 will pulse the PG output as the device determines if a battery is present. 2007-2015 Microchip Technology Inc. DS20002071C-page 19 MCP73837/8 6.0 APPLICATIONS The MCP73837/8 devices are designed to operate in conjunction with a host microcontroller or in stand-alone applications. The MCP73837/8 devices provide the preferred charge algorithm for Lithium-Ion and Lithium-Polymer cells, Constant-Current followed by Constant-Voltage. Figure 6-1 depicts a typical stand-alone MCP73837 application circuit, while Figure 6-2 and Figure 6-3 depict the accompanying charge profile. 1 2 USB Port CIN1 REGULATED WALL CUBE 1 CIN2 1 1 3 4 8 VAC VBAT VUSB THERM STAT1 V STAT2 PROG2 /PG PROG1 10 Thermistor 9 7 Low 6 R PROG IOUT 3.0 0.8 0.6 2.0 0.2 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 0.0 0.4 VDD = 5.2V RPROG = 1 kΩ 1200 mAh Li-Ion Battery Time (Minutes) FIGURE 6-2: Typical Charge Profile (1200 mAh Li-Ion Battery). DS20002071C-page 20 4.5 1.2 VOUT 4.0 Battery Voltage (V) 1 3.5 0.9 3.0 IOUT 2.5 0.6 2.0 1.5 VDD = 5.2V RPROG = 1 kΩ 1200 mAh Li-Ion Battery 1.0 0.5 0.3 0.0 Charge Current (A) 1.2 VOUT 4.0 1.0 Hi MCP73837 Typical Stand-Alone Application Circuit. Charge Current (A) Battery Voltage (V) 5.0 Single Li-Ion Cell 5 SS MCP73837 FIGURE 6-1: COUT 0 0 1 2 3 4 5 6 7 8 9 10 Time (Minutes) FIGURE 6-3: Typical Charge Profile in Thermal Regulation (1200 mAh Li-Ion Battery). 2007-2015 Microchip Technology Inc. MCP73837/8 6.1 Application Circuit Design 6.1.1.1 The preferred fast charge current for Lithium-Ion cells should always follow references and guidance from battery manufacturers. For example, programming 700 mA fast charge current for a 1000 mAh Li-Ion battery pack if its preferred fast charge rate is 0.7C. This will result in the shortest charge cycle time without degradation of a battery's life and performance. Due to the low efficiency of linear charging, the most important factors are thermal design and cost, which are a direct function of the input voltage, output current, and thermal impedance between the battery charger and the ambient cooling air. The worst-case situation is when the device has transitioned from the Preconditioning mode to the Constant Current mode. In this situation, the battery charger has to dissipate the maximum power. A trade-off must be made between the charge current, cost, and thermal requirements of the charger. 6.1.1 6.1.1.2 Selection of the external components in Figure 6-1 is crucial to the integrity and reliability of the charging system. The following discussion is intended as a guide for the component selection process. 1 USB Port CIN2 REGULATED 5V WALL CUBE 2 1 kΩ 3 SMAJ5.0A/AC SMAJ5.0A/AC Input Over-Voltage Protection Input over-voltage protection must be used when the input power source is hot-pluggable. This includes USB cables and wall-type power supplies. The cabling of these supplies acts as an inductor. When the supplies are connected/ disconnected from the system, large voltage transients are created which may damage the system circuitry. These transients should be snubbed out. A TransZorb® diode (unidirectional or bidirectional), connected from the VAC and VUSB inputs to 0V ground reference, will snub the transients. An example of this can be shown in Figure 6-4. COMPONENT SELECTION CIN1 Charge Current 1 kΩ 1 kΩ 4 8 VAC VBAT VUSB THERM /PG PROG2 PROG1 MCP73837 FIGURE 6-4: Thermistor 9 COUT Single Li-Ion Cell VSS 5 STAT1 STAT2 10 7 Low Hi 6 RPROG Input Over-Voltage Protection Example. 2007-2015 Microchip Technology Inc. DS20002071C-page 21 MCP73837/8 6.1.1.3 Thermal Considerations 6.1.1.5 Reverse-Blocking Protection The worst-case power dissipation in the battery charger occurs when the input voltage is at the maximum and the device has transitioned from the Preconditioning mode to the Constant-current mode. In this case, the power dissipation is: The MCP73837/8 provides protection from a faulted or shorted input. Without the protection, a faulted or shorted input would discharge the battery pack through the body diode of the internal pass transistor. EQUATION 6-1: The current regulation set input pin (PROG1/2) can be used to terminate a charge at any time during the charge cycle, as well as to initiate a charge cycle or a recharge cycle. PowerDissipation = V DDMAX –V PTHMIN I REGMAX Where: VDDMAX = the maximum input voltage IREGMAX = the maximum fast charge current VPTHMIN = the minimum transition threshold voltage 6.1.1.6 Placing a programming resistor from the PROG1 input to VSS or driving PROG2 to logic High or Low enables the device. Allowing either the PROG1/2 input to float disables the device and terminates a charge cycle. When disabled, the device’s supply current is reduced to 75 µA, typically. 6.1.1.7 For example, power dissipation with a 5V, ±10% input voltage source, and a 500 mA, ±10% fast charge current is calculated in the following example: EXAMPLE 6-1: PowerDissipation = 5.5V – 2.7V 550 mA = 1.54W Charge Inhibit Temperature Monitoring The charge temperature window can be set by placing fixed value resistors in series-parallel with a thermistor. The resistance values of RT1 and RT2 can be calculated with the following equations in order to set the temperature window of interest. For NTC thermistors, see Equation 6-2. EQUATION 6-2: RT2 RCOLD 24k = RT1 + --------------------------------RT2 + R COLD This power dissipation with the battery charger in the MSOP-10 package will cause thermal regulation to be entered as depicted in Figure 6-3. Alternatively, the 3 mm x 3 mm DFN package could be utilized to reduce the charge cycle times. 6.1.1.4 External Capacitors The MCP73837/8 is stable with or without a battery load. In order to maintain good AC stability in the Constant Voltage mode, a minimum capacitance of 1 µF is recommended to bypass the VBAT pin to VSS. This capacitance provides compensation when there is no battery load. In addition, the battery and interconnections appear inductive at high frequencies. These elements are in the control feedback loop during Constant Voltage mode. Therefore, the bypass capacitance may be necessary to compensate for the inductive nature of the battery pack. Virtually any good quality output filter capacitor can be used, independent of the capacitor’s minimum Effective Series Resistance (ESR) value. The actual value of the capacitor (and its associated ESR) depends on the output load current. A 1 µF ceramic, tantalum, or aluminum electrolytic capacitor at the output is usually sufficient to ensure stability for output currents up to 500 mA. DS20002071C-page 22 RT2 RHOT 5k = RT1 + -----------------------------R T2 + RHOT Where: RT1 = the fixed series resistance RT2 = the fixed parallel resistance RCOLD = the thermistor resistance at the lower temperature of interest RHOT = the thermistor resistance at the upper temperature of interest For example, by utilizing a 10 k at +25°C NTC thermistor with a sensitivity index, , of 3892, the charge temperature range can be set to 0°C – +50°C by placing a 1.54 k resistor in series (RT1), and a 69.8 k resistor in parallel (RT2) with the thermistor. 6.1.1.8 Charge Status Interface A status output provides information on the state of charge. The output can be used to illuminate external LEDs or interface to a host microcontroller. Refer to Table 5-1 or Figure 4-1 for information on the state of the status output during a charge cycle. 2007-2015 Microchip Technology Inc. MCP73837/8 6.2 PCB Layout Issues For optimum voltage regulation, place the battery pack as close as possible to the device’s VBAT and VSS pins. This is recommended to minimize voltage drops along the high-current-carrying PCB traces. If the PCB layout is used as a heat sink, adding many vias in the heatsink pad can help conduct more heat to the backplane of the PCB, thus reducing the maximum junction temperature. 2007-2015 Microchip Technology Inc. DS20002071C-page 23 MCP73837/8 7.0 PACKAGING INFORMATION 7.1 Package Marking Information 10-Lead DFN Marking Code Part Number(1) Marking Code BABA BABB BABC BACA BACB BACC MCP73837T-FCI/MF MCP73837T-FJI/MF MCP73837T-NVI/MF MCP73838T-FCI/MF MCP73838T-FJI/MF MCP73838T-NVI/MF BABA BABB BABC BACA BACB BACC Part Number(1) Marking Code Part Number(1) Marking Code MCP73837-FCI/UN MCP73837-FJI/UN MCP73837-NVI/UN MCP73838-FCI/UN MCP73838-FJI/UN MCP73838-NVI/UN MCP73838-AMI/UN 837FCI 837FJI 837NVI 838FCI 838FJI 838NVI 838AMI MCP73837T-FCI/UN MCP73837T-FJI/UN MCP73837T-NVI/UN MCP73838T-FCI/UN MCP73838T-FJII/UN MCP73838T-NVI/UN MCP73838T-AMI/UN 837FCI 837FJI 837NVI 838FCI 838FJI 838NVI 838AMI Part Number(1) MCP73837-FCI/MF MCP73837-FJI/MF MCP73837-NVI/MF MCP73838-FCI/MF MCP73838-FJI/MF MCP73838-NVI/MF (2) Example: BABA 1539 256 Example: 10-Lead MSOP 837FCI 539256 Note 1: Consult Factory for Alternative Device Options. 2: Consult Factory for MSOP Package Availability. Legend: XX...X Y YY WW NNN e3 * Note: DS20002071C-page 24 Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week ‘01’) Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free. The Pb-free JEDEC designator ( e3 ) can be found on the outer packaging for this package. In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. 2007-2015 Microchip Technology Inc. MCP73837/8 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 2007-2015 Microchip Technology Inc. DS20002071C-page 25 MCP73837/8 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20002071C-page 26 2007-2015 Microchip Technology Inc. MCP73837/8 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 2007-2015 Microchip Technology Inc. DS20002071C-page 27 MCP73837/8 UN Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20002071C-page 28 2007-2015 Microchip Technology Inc. MCP73837/8 UN Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 2007-2015 Microchip Technology Inc. DS20002071C-page 29 MCP73837/8 10-Lead Plastic Micro Small Outline Package (UN) [MSOP] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20002071C-page 30 2007-2015 Microchip Technology Inc. MCP73837/8 APPENDIX A: REVISION HISTORY Revision C (November 2015) The following is the list of modifications: 1. 2. 3. 4. Added Section 6.1.1.2 “Input Over-Voltage Protection”. Added Figure 6-4. Added CN output option to “Operational Output Options” table in “Product Identification System”. Minor typographical errors. Revision B (December 2011) The following is the list of modifications: 1. 2. 3. 4. 5. 6. Updated the Functional Block Diagram on page 3. Added labels on the charts throughout Section 2.0 “Typical Performance Curves”. Updated text in Section 3.7 “USB Port Current Regulation Set (PROG2)”. Updated text in Section 4.4 “Preconditioning”. Updated text in Section 5.2.2 “USB port Current Regulation Select (PROG2)”. Added labels in Figure 6-2 and Figure 6-3. Revision A (November 2007) • Original Release of this Document. 2007-2015 Microchip Technology Inc. DS20002071C-page 31 MCP73837/8 NOTES: DS20002071C-page 32 2007-2015 Microchip Technology Inc. MCP73837/8 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. Device X/ XX Examples(1): XX a) b) c) d) Output Temp. Package Options* Device: e) MCP73837: 1A Fully Integrated Charger, PG function on pin 8 MCP73837T: 1A Fully Integrated Charger, PG function on pin 8 (Tape and Reel) MCP73838: 1A Fully Integrated Charger, TE function on pin 8 MCP73838T: 1A Fully Integrated Charger, TE function on pin 8 (Tape and Reel) f) g) h) i) j) k) l) Output Options(1) Refer to “Operational Output Options” table for different operational output options. Temperature: I Package Type: MF = 10-Lead Plastic Dual Flat, No Lead Package 3 x 3 x 0.9 mm Body, DFN UN = 10-Lead Plastic Micro Small Outline Package, MSOP (2) Note 1: 2: = -40C to +85C Consult the factory for alternative device options. Consult the factory for MSOP package availability. MCP73837-FCI/MF: 10-lead DFN package MCP73837-FJI/MF: 10-lead DFN package MCP73837-NVI/MF: 10-lead DFN package MCP73837T-FCI/MF: 10-lead DFN package, Tape and Reel MCP73837T-FJI/MF: 10-lead DFN package, Tape and Reel MCP73837T-NVI/MF: 10-lead DFN package, Tape and Reel MCP73837-FCI/UN: 10-lead MSOP package MCP73837-FJI/UN: 10-lead MSOP package MCP73837-NVI/UN: 10-lead MSOP package MCP73837T-FCI/UN: 10-lead MSOP package Tape and Reel MCP73837T-FJI/UN: 10-lead MSOP package Tape and Reel MCP73837T-NVI/UN: 10-lead MSOP package Tape and Reel a) b) c) d) MCP73838-FCI/MF: MCP73838-FJI/MF: MCP73838-NVI/MF: MCP73838T-FCI/MF: e) MCP73838T-FJI/MF: f) MCP73838T-NVI/MF: g) h) i) j) k) MCP73838-AMI/UN: MCP73838-FCI/UN: MCP73838-FJI/UN: MCP73838-NVI/UN: MCP73838T-AMI/UN: l) MCP73838T-FCI/UN: m) MCP73838T-FJI/UN: n) MCP73838T-FCI/UN: 10-lead DFN package 10-lead DFN package 10-lead DFN package 10-lead DFN package Tape and Reel 10-lead DFN package Tape and Reel 10-lead DFN package Tape and Reel 10-lead MSOP package 10-lead MSOP package 10-lead MSOP package 10-lead MSOP package 10-lead MSOP package Tape and Reel 10-lead MSOP package Tape and Reel 10-lead MSOP package Tape and Reel 10-lead MSOP package Tape and Reel OPERATIONAL OUTPUT OPTIONS Output Options VREG IPREG/IREG VPTH/VREG ITERM/IREG VRTH/VREG Timer Period AM BZ 4.20V 10% 71.5% 7.5% 96.5% 0 hours 4.20V 100% N/A 7.5% 96.5% 0 hours 6 hours FC 4.20V 10% 71.5% 7.5% 96.5% GP 4.20V 100% N/A 7.5% 96.5% 6 hours G8 4.20V 10% 71.5% 7.5% 96.5% 8 hours NV 4.35V 10% 71.5% 7.5% 96.5% 6 hours YA 4.40V 10% 71.5% 7.5% 96.5% 6 hours 6S 4.50V 10% 71.5% 7.5% 96.5% 6 hours B6 4.20V 10% 66.5% 5.0% 96.5% 4 hours CN 4.20V 10% 71.5% 20% 94% 4 hours FJ 4.20V 10% 71.5% 20% 94% 6 hours 2007-2015 Microchip Technology Inc. DS20002071C-page 33 MCP73837/8 NOTES: DS20002071C-page 34 2007-2015 Microchip Technology Inc. Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. • Microchip is willing to work with the customer who is concerned about the integrity of their code. • Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as “unbreakable.” Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights unless otherwise stated. Trademarks The Microchip name and logo, the Microchip logo, dsPIC, FlashFlex, flexPWR, JukeBlox, KEELOQ, KEELOQ logo, Kleer, LANCheck, MediaLB, MOST, MOST logo, MPLAB, OptoLyzer, PIC, PICSTART, PIC32 logo, RightTouch, SpyNIC, SST, SST Logo, SuperFlash and UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. The Embedded Control Solutions Company and mTouch are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, BodyCom, chipKIT, chipKIT logo, CodeGuard, dsPICDEM, dsPICDEM.net, ECAN, In-Circuit Serial Programming, ICSP, Inter-Chip Connectivity, KleerNet, KleerNet logo, MiWi, motorBench, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code Generation, PICDEM, PICDEM.net, PICkit, PICtail, RightTouch logo, REAL ICE, SQI, Serial Quad I/O, Total Endurance, TSHARC, USBCheck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries. GestIC is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip Technology Inc., in other countries. All other trademarks mentioned herein are property of their respective companies. © 2011-2015, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. ISBN: 978-1-63277-879-6 QUALITY MANAGEMENT SYSTEM CERTIFIED BY DNV == ISO/TS 16949 == 2011-2015 Microchip Technology Inc. Microchip received ISO/TS-16949:2009 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified. 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