QUICK START GUIDE FOR DC1584A LTC4070EDDB: Simple Low-Iq Battery Charger/Protector With NTC Thermistor Input DESCRIPTION Demonstration Circuit DC1584A is a Simple Low-Iq Battery Charger/Protector With NTC Thermistor featuring the LTC®4070EDDB. PERFORMANCE SUMMARY Specifications are at TA = 25°C SYMBOL VBUS PARAMETER Input voltage V(BAT) Battery Float Voltage I(BAT) Battery Charge Current CONDITIONS RLIMIT = 169Ω ‘VFLOAT’ jumper on 4.1V, Constant Voltage Mode. TNTC = 25°C Constant Current Mode, Vin = 12V, VCC = 3.8V MIN 10 4.059 TYP 12 49.7 MAX 16 4.141 UNITS V V mA QUICK START PROCEDURE Refer to Figure 1 for the proper measurement equipment setup and jumper settings and follow the procedure below. NOTE. When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the VBUS or Vcc and GND terminals. See Figure 2 for proper scope probe technique. 1. Set PS1 = 12V, PS2 = 3.6V, “VFLOAT” (JP2) to 4.1V. Observe I(VBUS) (AM1). The voltage on the battery is below the LTC4070EDDB’s float voltage. So all the current is flowing into the battery, and that current is (12V – 3.6V) /169(R1) = 49.7mA. 2. If “LBO” LED lit, decrease PS2 until off. Observe BAT (VM2). The LBO output goes high when the battery voltage is below 3.2V, but it has 200300mV of hysteresis. So it may not go low until 3.5V, with Vcc ↑. 3. Increase PS2 until LBO is lit. Observe BAT (VM2). 4. Increase PS2 until HBO lit. Observe BAT (VM2). The HBO LED will light when the battery voltage is within ~50mV of the float voltage. 5. Disconnect PS2, AM2, and 3.6Ω resistor. Observe BAT (VM2). The only limit to the Vcc voltage now is the LTC4070, so the voltage will rise to the float voltage. 6. Reset the Jumpers to their default position. 1 LTC4070EDDB AM1 - + - + AM2 PS1 4.35V - 5.5V supply 1A + + - + VM1 3.6Ω - Note: All connections from equipment should be Kelvin connected directly to the board pins which they are connected on this diagram and any input or output leads should be twisted pair. Figure 1. Proper Measurement Equipment Setup for DC1584A GND VIN Figure 2. Measuring Input or Output Ripple 2 + VM2 - PS2 0V - 5V supply - 1A E2 NTC GND 10V - 15V E1 E3 C1 1uF 25V 0603 10 % R6 10k R5 0 INT NTC JP3 EXT R3 10k R1 169 1% 2512 3 2 0 R4 NTC NTCBIAS ADJ 8 9 5 LBO HBO DRV 6 4 7 Charged Charging JP5 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. DESIGNER: G. Barbehenn ENGINEER: APPROVED: CHECKED: Charged Charging TECHNOLOGY 1K 5% R7 JP6 GND OPT BAT GND ENTC E4 E5 E6 GND LBO HBO BAT 75mA J1 DF3-3P-2DSA E7 E8 NJC A PPROVED DATE 10/15/09 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only 1 2 3 DESC RIPTION PRODUCTION RELEASE A REVISION HISTORY REV DATE: X SIZE DC1584A Wednesday , Nov ember 04, 2009 DWG NO. SHEET 1 OF 1 REV A LTC4070EDDB: SIMPLE LOW - Iq BATTERY CHARGER / PROTECTOR WITH NTC THERMISTOR INPUT TITLE: HBO D2 2 OPT OPT HBO LED R11 1.0 5% 100uF 6.3V 1206 20 % C3 OPT R10 1.0 5% 1 G. Barbehenn DRAWN: APPROVALS R8 1K 5% D1 LBO CONTRACT NO. Q1 FDN352AP OPT CUSTOMER NOTICE 1 R9 1.0 5% OPT LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 25 mils clearance OFF OFF Unless noted: Resistors: Ohms, 0402, 1%, 1/16W Capacitors: uF, 0402, 10%, 50V GND VCC C2 0.22uF 25V 0805 ON SHUNT JP4 ON JP7 LBO LED 25 mils clearance GND U1 LTC4070EDDB 25 mils clearance 1 JP2 VFLOAT OFF 25 mils clearance R2 200 4.2V 4.1V 4.0V JP1 VIN ON 2 3 VBUS 1 2 ECO LTC4070EDDB Figure 3. Schematic 3 LTC4070EDDB Figure 4. Bill of Materials 4