Demo Circuit 1592A-A/-B QUICK START GUIDE LTC3577-3 and LTC3577-4 LTC3577-3 AND LTC3577-4 Highly Integrated Portable Product PMIC DESCRIPTION sequence and reset, and a 10 LED string controller with WARNING gradation and PWM control. The three buck regulators and the LED Boost controller have adjustable slew rates Do not look directly at operating LED. for EMI reduction. This circuit produces light that can damage eyes. The LTC3577-3 and LTC3577-4 has a high temperature battery voltage reduction feature that reduces the battery Demo Circuit 1592A is a Highly Integrated Portable voltage under high temperature conditions to improve Product PMIC with a pushbutton controller, two LDOs, safety and reliability. three buck converters, a Li-Ion battery charger, and a power path controller featuring the LTC3577-3 and Refer to the LTC3577-3 and LTC3577-4 datasheet for 2 LTC3577-4. This board utilizes a DC590B, USB to I C more details on the electrical and timing specifications. interface board, to control the LTC3577-3/LTC377-4 Design files for this circuit board are available. Call software control window. the LTC factory. The LTC3577-3 and LTC3577-4 are PowerPath man- L, LTC, LTM, LT are registered trademarks of Linear Technology Corporation. PowerPath and Bat-Track are trademarks of Linear Technology Corporation. All other trademarks are the ager with automatic load prioritization, battery charger, property of their respective owners. Bat-Track controller, push button controlled power up PERFORMANCE SUMMARY Specifications are at T = 25C A PARAMETER CONDITIONS MIN TYP MAX UNITS Input Supply Range (V ) 4.35 5.5 V BUS Absolute Wall Input Threshold (V) V Rising 4.3 4.45 V W WALL V Falling 3.1 3.2 V WALL DV Operating Voltage 1.6 5.5 V CC DV UVLO (V 1 V CC DVCC,UVLO) V Regulated Output Voltage (V ) DC1592A-A (LTC3577-3) 4.179 4.200 4.221 V BAT FLOAT DC1592A-B (LTC3577-4) 4.079 4.100 4.121 V Constant Current Mode Charge Current (I ) R = 2K, Input current limit = 1A 465 500 535 mA CHRG PROG V UVLO V Falling 2.5 2.7 V OUT OUT V Rising 2.8 2.9 V OUT V 0 to 500mA 1.8 V OUT1 V 0 to 500mA 3.3 V OUT2 V 0 to 800mA 1.2 V OUT3 LDO1 0 to 150mA 3.3 V LDO2 0 to 150mA 1.2 V Full-Scale LED Current 20 mA 1LTC3577-3 AND LTC3577-4 QUICK START PROCEDURE Demo Circuit 1592 is designed to be used with a USB 6. With power off, connect a 5V, 1A power supply to input and/or a 5V adaptor input. Demo Circuit 1592 util- VUSB and GND with a series ammeter and a voltmeter 2 izes the DC590B, USB to I C interface board, to control as shown in XFigure 1X. the LED boost driver, LDO enables, and buck modes. It is 7. Connect a battery or a battery simulator set to 3.6V also used to monitor the buck and LDO outputs, plus between BAT and GND with a series ammeter and a battery charger status. This circuit may be evaluated us- voltmeter as shown in XFigu re 1. X ing a lithium ion battery or a battery simulator consist- Turn on and set the VUSB input power supply to 5V. ing of a 0V-5V, 3A power supply and a 3.6 power 8. The DC590B board gets its power from the USB cable. resistor. Run the QuikEval.exe program. The LTC3577- The DC1592 is easy to set up to evaluate the perform- 9. 3/LTC3577-4 control window (shown in XFigu re 3X) ance of the LTC3577-3 and LTC3577-4. Refer to FiX gure 1X pops up. and Figure 2 for proper measurement equipment setup and follow the procedure below to evaluate using the NOTE. The Status indicators on the software control window may display 2 N/A when an I C ACK was not received. This occurs when the part is in DC590B board: the power down (PDN) state or when DVCC is missing. Please refer to NOTE. When measuring the input or output voltage ripple, care must be the LTC3577 datasheet for more information on the PDN state. 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 10. On the LTC3577-3/LTC3577-4 control window, se- the VUSB, WALL, or VOUT and GND terminals. See XFig ure 2X for proper lect the PWR ON HI/LOW button. When HI is indi- scope probe technique. cated on the button, the PWR ON pin goes high and TM 1. Refer to the DC590B Quick Start Guide for QuikEval the LDO2, VOUT1, and VOUT2 outputs sequence up. setup and software installation details. VOUT POWER GOOD for each output is indicated on the STATUS section on the control window. 2. Set the VCCIO jumper, JP6, on the DC590B board to the 3.3V position. 11. On the LTC3577-3/LTC3577-4 control window, se- lect the EN3 HI/LOW button. When HI is indicated NOTE. The DVCC voltage level may be selected on the DC590B. This is done by setting the VCCIO jumper, JP6, on the DC590B board to one of on the button, the EN3 pin goes high and the VOUT3 the following settings: 3.3V, 5V, removed for 2.7V or set to external if an powers up. VOUT POWER GOOD for VOUT3 is indi- external supply is desired to be used. cated on the STATUS section on the control window. 3. Make sure the USB cable is connected between the 12. On the LTC3577-3/LTC3577-4 control window, se- computer and the DC590B controller board. lect the BUCK1 through BUCK3 MODE buttons to 4. Set the jumpers on the DC1592 board to the following switch the bucks into Burst mode. Observe the output settings: ripple and the quiescent current before and after switching modes. JP1. ILIM0 to 0 position. 13. Select the desired BUCK SW SLEW RATE option but- JP2. ILIM1 to 0 position. ton to switch between a fast rise-time for best effi- JP3. NTC to INT position. ciency to a slower rise time with better EMI perform- ance. JP4. PWR ON CNTL to SW position. 14. Set the LED DAC REG vertical slider to a desired cur- JP5. VINLDO2 to VOUT position. rent level. The LED current and the LED DAC register 5. Connect DC1592 to the DC590B USB Serial Controller setting are displayed in the test boxes below the verti- using the supplied 14-conductor ribbon cable as cal slider. The LED full scale current (I ) for this LED(FS) shown in X Figure 1.X circuit is 20mA. 2