19-2899; Rev 1; 11/03 KIT ATION EVALU E L B AVAILA Linear Li+ Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN Features The MAX1507 is an intelligent, stand-alone constant-current, constant-voltage (CCCV), thermally regulated linear charger for a single-cell lithium-ion (Li+) battery. The MAX1507 integrates the current-sense circuit, MOS pass element, and thermal-regulation circuitry, and also eliminates the reverse-blocking Schottky diode to create the simplest and smallest charging solution for hand-held equipment. The MAX1507 functions as a stand-alone charger to control the charging sequence from the prequalification state through fast-charge, top-off charge, and fullcharge indication. 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 IC. ♦ Stand-Alone Linear 1-Cell Li+ Battery Charger The MAX1507 achieves high flexibility by providing an adjustable fast-charge current and thermal regulation setpoints. Other features include the charging status (CHG) of the battery and an active-low control input (EN). The MAX1507 accepts a +4.25V to +13V supply, but disables charging when the input voltage exceeds +7V to protect against unqualified or faulty AC adapters. The MAX1507 operates over the extended temperature range (-40°C to +85°C) and is available in a compact 8-pin thermally enhanced 3mm x 3mm Thin DFN package with 0.8mm height. ♦ Soft-Start Limits Inrush Current ♦ No External FET, Reverse-Blocking Diode, or Current-Sense Resistor Required ♦ Programmable Fast-Charge Current (0.8A max) ♦ Proprietary Programmable Die-Temperature Regulation Control (+90°C, +100°C, and +130°C) ♦ +4.25V to +13V Input Voltage Range with Input Overvoltage Protection (OVP) Above +7V ♦ Charge-Current Monitor for Fuel Gauging ♦ Low Dropout Voltage—130mV at 0.425A ♦ Input Power-Source Detection Output (VL) and Charge-Enable Input (EN) ♦ Charge Status Output (CHG) for LED or Microprocessor Interface ♦ Small 3mm x 3mm 8-Pin Thin DFN Package, 0.8mm High Ordering Information PART TEMP RANGE PIN-PACKAGE TOP MARK Cellular and Cordless Phones MAX1507ETA -40°C to +85°C 8 Thin DFN-EP* AGW PDAs *EP = Exposed paddle. Applications Digital Cameras and MP3 Players USB Appliances Typical Operating Circuit Charging Cradles and Docks Bluetooth™ Equipment BATT TEMP EN TOP VIEW CHG Pin Configuration 8 7 6 5 INPUT 4.25V TO 13V IN BATT 1µF 1µF Li+ 4.2V MAX1507 CHG MAX1507 ISET OFF 1 2 3 4 VL IN GND ISET ON EN TEMP VL GND 2.80kΩ 0.47µF 3mm x 3mm THIN DFN Bluetooth is a trademark of Ericsson. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX1507 General Description MAX1507 Linear Li+ Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN ABSOLUTE MAXIMUM RATINGS IN, CHG to GND .....................................................-0.3V to +14V VL, BATT, ISET, EN, TEMP to GND ..........................-0.3V to +6V VL to IN...................................................................-14V to +0.3V IN to BATT Continuous Current.............................................0.9A Continuous Power Dissipation (TA = +70°C) 8-Pin TDFN (derate 24.4mW/°C above+70°C) ..........1951mW Short-Circuit Duration.................................................Continuous Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C 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 = 5V, VBATT = 4.0V, TEMP = EN = CHG = unconnected, RISET = 2.8kΩ to GND, CVL = 0.47µF, BATT bypassed to GND with 1µF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER CONDITIONS Input Voltage Range Input Operating Range ACOK Trip Point, IN Overvoltage Lockout Trip Point MIN TYP V 4.25 6.50 V VIN - VBATT, VIN rising 20 40 60 VIN - VBATT, VIN falling 15 30 45 VIN rising 6.5 7 7.5 VIN hysteresis 0.11 Charging (IIN - IBATT) 1 2 0.8 1.5 Disabled, EN = VL VL Output Voltage IVL = 100µA 3.3 VL Load Regulation IVL = 100µA to 2mA -71 VL Temperature Coefficient IVL = 100µA OFF state (VIN = VBATT = 4.0V) BATT Input Current Hysteresis 0.17 3 10 4 10 Maximum RMS Charge Current 2 0.8 µA A TA = 0°C to +85°C 4.162 4.2 4.238 TA = -40°C to +85°C 4.150 4.2 4.250 4.4 4.67 4.9 _______________________________________________________________________________________ mV V VIN = 0 to 4V VBATT rising mA mV/°C EN = VL BATT Removal Detection Threshold V V -200 -2 2.95 IBATT = 0 mV 0.065 VIN rising Battery Regulation Voltage UNITS 13 IN Input Current VL Undervoltage Lockout Trip Point MAX 0 V V Linear Li+Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN (VIN = 5V, VBATT = 4.0V, TEMP = EN = CHG = unconnected, RISET = 2.8kΩ to GND, CVL = 0.47µF, BATT bypassed to GND with 1µF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER CONDITIONS MIN BATT Removal Detection-Threshold Hysteresis MAX 200 Minimum BATT Bypass Capacitance VBATT = 3.5V Precharge Current System Accuracy Percentage of the fast-charge current, VBATT = 2.2V 520 562 mA 5 10 15 % 130 TEMP = floating 100 TEMP = GND VBATT rising Current-Sense Amplifier Gain, ISET to IBATT in Fast Charge Mode IBATT = 500mA, VISET = 1.4V Regulator Dropout Voltage (VIN - VBATT ) VBATT = 4.1V, IBATT = 425mA EN Logic Input Low Voltage 4.25V < VIN < 6.5V EN Logic Input High Voltage 4.25V < VIN < 6.5V V CHG = 13V Full Battery Detection Current Threshold (as a Percentage of the Fast-Charge Current) IBATT falling 2.3 2.5 2.7 V 0.880 0.958 1.035 mA/A 130 200 mV 0.52 V 1.3 EN Internal Pulldown Resistor CHG Output High Leakage Current °C 90 VBATT Precharge Threshold Voltage V CHG = 1V µF/A 478 TEMP = VL CHG Output Low Current UNITS mV 1 Fast-Charge Current-Loop System Accuracy Die-Temperature-Regulation Set Point TYP V 100 200 400 kΩ 5 12 20 mA TA = +25°C 1 TA = +85°C 0.002 5 10 15 µA % Note 1: Limits are 100% production tested at TA = +25°C. Limits over operating temperature range are guaranteed through correlation using statistical quality control (SQC) methods. _______________________________________________________________________________________ 3 MAX1507 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VIN = 5V, VBATT = 4.0V, TEMP = EN = CHG = unconnected, RISET = 2.8kΩ to GND, CIN = 1µF, CBATT = 1µF, CVL = 0.47µF, TA = +25°C, unless otherwise noted.) 1.0 0.5 1.0 0.5 2 4 6 8 12 10 300 200 0 0 2 4 6 8 10 0 12 1 2 3 4 BATTERY VOLTAGE (V) CHARGE CURRENT vs. INPUT VOLTAGE CHARGE CURRENT vs. INPUT-VOLTAGE HEADROOM BATTERY REGULATION VOLTAGE vs. TEMPERATURE VBATT = 4.0V INPUT VOLTAGE (V) VIN - VBATT (V) 520 500 480 460 -15 10 35 60 MAX1507 toc08 VBATT = 3.6V 400 300 0 85 VBATT = 4.0V 500 100 60 -40 600 400 35 4.186 700 200 10 4.189 800 420 AMBIENT TEMPERATURE (°C) 4.192 900 440 -15 4.195 1000 CHARGE CURRENT (mA) 540 -40 4.198 CHARGE CURRENT vs. AMBIENT TEMPERATURE (TEMP = VL) MAX1507 toc07 560 4.201 TEMPERATURE (°C) CHARGE CURRENT vs. AMBIENT TEMPERATURE TEMP = VL 4.204 4.180 0 0.04 0.08 0.12 0.16 0.20 0.24 0.28 0.32 0.36 0.40 580 4.207 4.183 0 1 2 3 4 5 6 7 8 9 10 11 12 13 600 4.210 MAX1507 toc06 600 550 500 450 400 350 300 250 200 150 100 50 0 BATTERY REGULATION VOLTAGE (V) CHARGE CURRENT (mA) TEMP = VL MAX1507 toc05 INPUT VOLTAGE (V) MAX1507 toc04 INPUT VOLTAGE (V) 600 550 500 450 400 350 300 250 200 150 100 50 0 CHARGE CURRENT (mA) 400 100 0 0 TEMP = VL 500 1.5 0 4 600 MAX1507 toc02 EN = VL CHARGE CURRENT (mA) 1.5 2.0 DISABLED-MODE SUPPLY CURRENT (mA) IBATT = 0 MAX1507 toc01 2.0 SUPPLY CURRENT (mA) CHARGE CURRENT vs. BATTERY VOLTAGE DISABLED-MODE SUPPLY CURRENT vs. INPUT VOLTAGE MAX1507 toc03 SUPPLY CURRENT vs. INPUT VOLTAGE CHARGE CURRENT (mA) MAX1507 Linear Li+ Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN RISET = 1.87kΩ -40 -15 10 35 60 AMBIENT TEMPERATURE (°C) _______________________________________________________________________________________ 85 85 Linear Li+ Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN (VIN = 5V, VBATT = 4.0V, TEMP = EN = CHG = unconnected, RISET = 2.8kΩ to GND, CIN = 1µF, CBATT = 1µF, CVL = 0.47µF, TA = +25°C, unless otherwise noted.) CHARGE CURRENT vs. AMBIENT TEMPERATURE (TEMP = GND) CHARGE CURRENT vs. AMBIENT TEMPERATURE (TEMP = OPEN) 700 600 500 VBATT = 3.6V 400 300 VBATT = 4.0V 900 800 CHARGE CURRENT (mA) CHARGE CURRENT (mA) 800 1000 MAX1507 toc10 VBATT = 4.0V 900 MAX1507 toc09 1000 700 600 500 VBATT = 3.6V 400 300 200 200 100 RISET = 1.87kΩ 100 RISET = 1.87kΩ 0 0 -40 -15 10 35 60 -40 85 -15 10 35 60 85 AMBIENT TEMPERATURE (°C) AMBIENT TEMPERATURE (°C) Pin Description PIN NAME 1 VL Internally Generated Logic Supply for Chip. Bypass VL to GND with a 0.47µF capacitor. FUNCTION 2 IN Input Supply Voltage. Bypass IN to GND with a 1µF capacitor to improve line noise and transient rejection. 3 GND Ground. Connect GND and exposed pad to a large copper trace for maximum power dissipation. 4 ISET Charge-Current Program and Fast-Charge Current Monitor. Output current from ISET is 0.958mA per amp of battery charging current. The charging current is set by connecting a resistor from ISET to GND. Fast-charge current = 1461V / RISETΩ. 5 EN Logic-Level Enable Input. Drive EN high to disable charger. Pull EN low or float for normal operation. EN has an internal 200kΩ pulldown resistor. 6 TEMP Three-Level Input Pin. Connect TEMP to VL, GND, or leave floating. Sets maximum die temperature for thermal regulation loop. Connection to GND = +90°C, floating = +100°C, VL = +130°C. TEMP is Hi-Z during shutdown. 7 BATT Li+ Battery Connection. Bypass BATT to GND with a capacitor of at least 1µF per ampere of charge current. 8 CHG Charging Indicator, Open-Drain Output. CHG goes low (and can turn on an LED) when charging begins. CHG is high impedance when the battery current drops below 10% of the fast-charging current, or when EN is high. Connect a pullup resistor to the µP’s I/O voltage when interfacing with a µP logic input. — PAD Exposed Pad. Connect exposed pad to a large copper trace for maximum power dissipation. The pad is internally connected to GND. _______________________________________________________________________________________ 5 MAX1507 Typical Operating Characteristics (continued) MAX1507 Linear Li+ Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN Detailed Description state. Once the cell has passed 2.5V, the charger softstarts before it enters the fast-charge stage. The fastcharge current level is programmed through a resistor from ISET to ground. As the battery voltage approaches 4.2V, the charging current is reduced. If the battery current drops to less than 10% of the fast-charging current, the CHG indicator goes high impedance, signaling the battery is fully charged. At this point the MAX1507 enters a constant voltage-regulation mode to The MAX1507 charger uses voltage, current, and thermal-control loops to charge a single Li+ cell and to protect the battery (Figure 1). When a Li+ battery with a cell voltage below 2.5V is inserted, the MAX1507 charger enters the prequalification stage where it precharges that cell with 10% of the user-programmed fast-charge current. The CHG indicator output is driven low (Figure 2) to indicate entry into the prequalification MAX1507 BATT IN VREF OUTPUT DRIVER, CURRENT SENSE, AND LOGIC ISET TEMPERATURE SENSOR +90°C +100°C +130°C IREF IN VL TEMP IN VL 0.47µF BATT VLUVLO REF IN VINOVLO VLOK EN ON INOK LOGIC REFOK CHG 200kΩ REFOK N GND Figure 1. Functional Diagram 6 _______________________________________________________________________________________ Linear Li+Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN MAX1507 ASYNCHRONOUS FROM ANYWHERE VIN > 7V + VBATT > VIN + EN = HIGH SHUTDOWN VBATT < 2.5V D AN D 7V T AN < T A V IN > V B V IN = LOW EN PRECHARGE 10% CHARGE CURRENT LED = ON CHARGER = OFF LED = OFF VIN > 7V + VBATT > VIN + EN = HIGH VBATT < 2.4V VBATT > 2.5V FAST CHARGE 100% CHARGER CURRENT LED = ON ICHARGE < 10% OF ISET ICHARGE > 20% OF ISET FULL BATT LED = OFF FULL BATT CONTINUES TO REGULATE BATT UP TO 4.2V Figure 2. Charge State Diagram maintain the battery at full charge. If, at any point while charging the battery, the die temperature approaches the user-selected temperature setting (TEMP pin), the MAX1507 reduces the charging current so the die temperature does not exceed the temperature-regulation set point. The thermal-regulation loop limits the MAX1507 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 MAX1507 from overheating, but also allows higher charge current without risking damage to the system. EN Charger Enable Input EN is a logic input (active low) to enable the charger. Drive EN low, leave floating, or connect to GND to enable the charger control circuitry. Drive EN high to disable the charger control circuitry. EN has a 200kΩ internal pulldown resistance. VL Internal Voltage Regulator The MAX1507 linear charger contains an internal linear regulator available on the VL output pin. VL requires a 0.47µF ceramic bypass capacitor to GND. VL is regulated to 3.3V whenever the input voltage is above 3.5V. _______________________________________________________________________________________ 7 MAX1507 Linear Li+ Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN CHG Charge Indicator Output to the value set by TEMP. The MAX1507 operates normally while the thermal loop is active. An active thermal loop does not indicate a fault condition. TEMP allows the MAX1507 to maximize the charge current while providing protection against excessive power dissipation. Connect TEMP to GND to regulate the die temperature at +90°C. Leave TEMP floating to regulate the die temperature at +100°C. Connect TEMP to VL to regulate the die temperature at +130°C. CHG is an open-drain current source for indicating charge status. Table 1 describes the state of CHG during different stages of operation. CHG is a nominal 12mA current source suitable for driving a charge-indication LED. If the MAX1507 is used in conjunction with a microprocessor, a pullup resistor to the logic I/O voltage allows CHG to indicate charge status to the µP instead of driving an LED. Capacitor Selection Soft-Start Connect a ceramic capacitor from BATT to GND for proper stability. Use a 1µF X5R ceramic capacitor for most applications. Connect a 1µF ceramic capacitor from IN to GND. Use a larger input bypass capacitor for high input voltages or high charging currents to reduce supply noise. Connect a 0.47µF ceramic capacitor from VL to GND. An analog soft-start algorithm activates when entering fast-charge mode. When the prequalification state is complete (VBATT exceeds +2.5V), the charging current ramps up in 3ms to the full charging current. This reduces the inrush current on the input supply. Applications Information Charge-Current Selection Thermal Considerations The maximum charging current is programmed by an external RISET resistor connected from ISET to GND. Select the RISET value based on the following formula: IFAST= 1461V / RISETΩ where IFAST is in amps and RISET is in ohms. ISET can also be used to monitor the fast-charge current level. The output current from the ISET pin is 0.958mA per amp of charging current. The output voltage at ISET is proportional to the charging current as follows: VISET = (ICHG x RISET) / 1044 The MAX1507 is in a thermally enhanced thin DFN package with exposed paddle. Connect the exposed paddle of the MAX1507 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 MAX1507 to charge the battery with maximum current, while minimizing the increase in die temperature. DC Input Sources The MAX1507 operates from well-regulated DC sources. The full-charging input-voltage range is 4.25V to 7V. The device can stand up to 13V on the input without damage to the IC. If VIN is greater than 7V, then the MAX1507 stops charging. An appropriate power supply must provide at least 4.25V when sourcing the desired peak charging current. It also must stay below 6.5V when unloaded. The voltage at ISET is nominally 1.4V at the selected fast-charge current, and falls with charging current as the cell becomes fully charged. Thermal-Regulation Selection Set the regulated die temperature of the MAX1507 with the TEMP three-level logic input. The MAX1507 reduces the charge current to limit the die temperature Table 1. CHG States EN VIN VBATT IBATT CHG X VBATT VIN 0 Hi-Z Shutdown Low 4.25V ≤ VIN ≤ 7V < 2.5V 10% of IFAST Low Prequalification Low 4.25V ≤ VIN ≤ 7V ≥ 2.5V IFAST* Low Fast Charge Low 4.25V ≤ VIN ≤ 7V 4.2V 10% of IFAST Hi-Z Full Charge Low >7V X 0 Hi-Z Overvoltage High X X 0 Hi-Z Disabled STATE X = Don’t care. *IFAST is reduced as necessary to maintain the die temperature set by the TEMP input. 8 _______________________________________________________________________________________ Linear Li+Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN Microprocessor-Interfaced Charger Figure 3 shows the MAX1507 as a µP-cooperated Li+ battery charger. The MAX1507 starts charging the battery when EN is low. The µP can drive EN high to disable the charger. Use a logic-biased NPN transistor as an inverter circuit to generate an AC_ON signal for the system to detect the presence of an input supply. CHG can be used to detect the charge status of a battery. By monitoring V ISET , the system can measure the charge current. 4.2V Li+ AC/DC ADAPTER IN BATT 1µF 1µF VI/O MAX1507 CHG GND AC_ON ROHM DTC114EM TEMP SYSTEM VL 0.47µF ISET EN 2.8kΩ CHARGE-CURRENT MONITOR VI/O LOW: CHARGE, HIGH: FULL OR OFF Figure 3. µP Interfaced Li+ Battery Charger _______________________________________________________________________________________ 9 MAX1507 USB-Powered Li+ Charger The universal serial bus (USB) provides a high-speed serial communication port as well as power for the remote device. The MAX1507 can be configured to charge its battery at the highest current possible from the host port. Figure 4 shows the MAX1507 as a USB battery charger. To make the circuit compatible with either 100mA or 500mA USB ports, the circuit initializes at 95mA charging current. The microprocessor then interrogates the host to determine its current capability. If the host port is capable, the charging current is increased to 435mA. The 435mA current was chosen to avoid exceeding the 500mA USB specification. Application Circuits Stand-Alone Li+ Charger The MAX1507 provides a complete Li+ charging solution. The Typical Application Circuit on the front page shows the MAX1507 as a stand-alone Li+ battery charger. The 2.8kΩ resistor connected to ISET sets a charging current of 520mA. The LED indicates when either fast-charge or precharge qualification has begun. When the battery is full, the LED turns off. MAX1507 Linear Li+ Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN 4.2V Li+ VBUS GND IN BATT 1µF 1µF VI/O MAX1507 GND CHG ROHM DTC114EM TEMP SYSTEM VL 0.47µF USB PORT EN ISET 15.4kΩ HIGH: 435mA, LOW: 95mA 4.3kΩ N VI/O D+ D- Figure 4. USB Battery Charger Layout and Bypassing Connect a 1µF ceramic input capacitor as close to the device as possible. 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 accurate battery voltage sensing. Make all high-current traces short and wide to minimize voltage drops. For an example layout, refer to the MAX1507/MAX1508 evaluation kit layout. 10 Chip Information TRANSISTOR COUNT: 1812 PROCESS: BiCMOS ______________________________________________________________________________________ Linear Li+Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN 6, 8, &10L, DFN THIN.EPS D N PIN 1 INDEX AREA E E2 DETAIL A CL CL L A L e e PACKAGE OUTLINE, 6, 8, 10 & 14L, TDFN, EXPOSED PAD, 3x3x0.80 mm NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY 21-0137 F 1 2 ______________________________________________________________________________________ 11 MAX1507 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) MAX1507 Linear Li+ Battery Charger with Integrated Pass FET and Thermal Regulation in 3mm x 3mm Thin DFN Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) COMMON DIMENSIONS SYMBOL A MIN. 0.70 0.80 D 2.90 3.10 E 2.90 3.10 A1 L 0.00 0.05 k MAX. 0.40 0.20 0.25 MIN. A2 0.20 REF. PACKAGE VARIATIONS PKG. CODE N D2 E2 e JEDEC SPEC b [(N/2)-1] x e T633-1 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF T833-1 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF T1033-1 10 1.50±0.10 2.30±0.10 0.50 BSC MO229 / WEED-3 0.25±0.05 2.00 REF T1433-1 14 1.70±0.10 2.30±0.10 0.40 BSC ---- 0.20±0.03 2.40 REF T1433-2 14 1.70±0.10 2.30±0.10 0.40 BSC ---- 0.20±0.03 2.40 REF PACKAGE OUTLINE, 6, 8, 10 & 14L, TDFN, EXPOSED PAD, 3x3x0.80 mm 21-0137 F 2 2 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.