ACT2802 Demo Board Application Report Rev 2.0, 005-Aug-2014 Dedicated 5V/2.1A Power Bank Solution FEATURES 5V/3.0A input current limit 2.0A battery charge current 5V/2.1A boost output current 2.5A boost oost output constant current limit 5.0V+/- 100mV output voltage Programmable 4.1V to 4.35V battery voltage Single chip integration solution with minimal component count Prioritized power path from input to output 92% charge efficiency and 95% efficiency for boost Accommodation for 10mA-2400mA 2400mA input source Battery disconnected at output short to ground 550kHz switching frequencies allowing 2.2µH 2.2 inductor <10uA battery drain current in HZ mode Boost shuts down at no load and turns on by push button 4 LEDs indicating battery level and charge status with impedance compensation Preconditioning, fast charge, top off and end of charge in battery charge mode Battery temperature monitoring and thermal protection Low battery level alarm 4.6V battery over voltage protection Charge current foldback at 110℃ die temperature IC over temperature protection TQFN4x4-24 package SPECIFICATION Input voltage 4.7 - 5.5V Active-Semi, Semi, Inc. Boost output voltage Input current limit Battery charge current Boost output current limit 5.0V 3.0A 2.0A 2.5A -1- www.active-semi.com ACT2802: Dedicated 5V/2.1A Power Bank Solution TABLE OF CONTENT 1 DEMO BOARD PHOTOS .................................................................................................................................................. 3 2 SCHEMATICS ..................................................................................................................................................................... 3 3 BILL OF MATERIALS ....................................................................................................................................................... 4 4 PCB LAYOUT ...................................................................................................................................................................... 5 5 FUNCTIONAL TEST .......................................................................................................................................................... 5 5.1 BATTERY CHARGE V/I PROFILE ...................................................................................................................................... 5 5.2 POWER PATH FUNCTION ................................................................................................................................................. 5 5.3 CHARGE EFFICIENCY ...................................................................................................................................................... 6 5.4 BOOST OUTPUT REGULATION ......................................................................................................................................... 7 5.5 BOOST EFFICIENCY AND POWER LOSS (TA=25℃) .......................................................................................................... 7 5.6 BOOST STANDBY POWER (TA=25℃) .............................................................................................................................. 8 5.7 BOOST CONSTANT CURRENT AND CONSTANT VOLTAGE REGULATION (TA=25℃) ......................................................... 8 5.8 BATTERY LEAKAGE CURRENT IN HZ MODE ................................................................................................................... 9 5.9 RIPPLE AND NOISE ........................................................................................................................................................ 10 5.10 LOAD DYNAMIC RESPONSE LOAD STEP (VBAT=3.7V) ................................................................................................. 10 5.11 LED INDICATION .......................................................................................................................................................... 10 5.12 SYSTEM MANAGEMENT................................................................................................................................................ 11 5.13 KEY COMPONENTS TEMPERATURE TEST (TA=40℃, BURNING FOR 2 HOURS) ............................................................... 11 6 PCB LAYOUT GUIDANCE ..................................................................................................................................... 12 7 EMI TEST .......................................................................................................................................................................... 14 Active-Semi, Inc. www.active-semi.com - - 2 ACT2802: Dedicated 5V/2.1A Power Bank Solution 1 DEMO BOARD PHOTOS (DEMO BOARD SIZE: 46.5mm*23mm) LED indication Input USB Push button Output USB 2 SCHEMATICS R4 ACT2802 ICST R3 C11 nPG IOST ILIM CSN VIN CSP B AT PGND SW R10 SW D- VOUT + VOUT R1 C12 Input USB D+ - LED2 LED3 LED4 RIMC BLVS FLD R5 BTV AGND R11 L ED1 LED 1 PB R13 L ED2 L ED3 HZ L ED4 PB R8 R23 R7 R6 R12 C6 C9 C10 D2 C3 C8 R18 C2 R24 R25 D1 Q1 R2 + L1 D- R9 Q3 D+ - R20 C7 Output USB R15 R14 Active-Semi, Inc. www.active-semi.com R17 C16 R21 R2A C5 C13 C4 BAT C14 R16 - - 3 ACT2802: Dedicated 5V/2.1A Power Bank Solution 3 BILL OF MATERIALS Item Reference Description QTY Manufacturer 1 L1 Core 6.5*3*3 Dip 2.2uH 6A 1 Sunlord 2 Q1 AO4503, Rdson=19mÙ at VGS = - 4.5 V 1 Vishay 3 Q3 MMBT3906 1 Vishay 4 D1 SBR3U20SA, 20V/3A Schottky 1 Diodes 5 D2 1N4148, Vf=0.7V, 75V Schottky 1 Vishay 6 C2,C5,C13,C14 Ceramic capacitor, 22uF/10V, X7R, 1206 4 Murata/TDK 7 C3 Ceramic capacitor, 4.7uF/10V, X7R, 1206 1 Murata/TDK 8 C4 Ceramic capacitor, 0.1uF/10V, X7R, 0603 1 Murata/TDK 9 C6 Ceramic capacitor, 10nF/10V, X7R, 0603 1 Murata/TDK 10 C7 Ceramic capacitor, 4.7nF/10V, X7R, 0603 1 Murata/TDK 11 C8,C11,C12 Ceramic capacitor, 2.2uF/10V, X7R, 0603 3 Murata/TDK 12 C9,C10 Ceramic capacitor, 39pF/10V, X7R, 0603, Optional 2 Murata/TDK 13 C16 Ceramic capacitor, 4.7uF/10V, X7R, 0603 1 Murata/TDK 14 R1 Chip Resistor, 750Ù, 1/10W, 1%, 0603 1 Murata/TDK 15 R2,R2A Chip Resistor, 50mÙ, 1/4W, 1%, 1206 2 Murata/TDK 16 R3 Chip Resistor, 93.1kÙ, 1/10W, 1%, 0603 1 Murata/TDK 17 R4,R15 Chip Resistor, 43.2kÙ, 1/10W, 1%, 0603 2 Murata/TDK 18 R5 Chip Resistor, 25kÙ, 1/10W, 1%, 0603 1 Murata/TDK 19 R6 Chip Resistor, 10kÙ, 1/10W, 5%, 0603 1 Murata/TDK 20 R7 Chip Resistor, 60kÙ, 1/10W, 1%, 0603 1 Murata/TDK 21 R8 Chip Resistor, 80kÙ, 1/10W, 1%, 0603 1 Murata/TDK 22 R9 Chip Resistor, 0.47Ù, 1/8W, 5%, 0805 1 Murata/TDK 23 R10 Chip Resistor, 2.7Ù, 1/4W, 5%, 1206 1 Murata/TDK 24 R11 Chip Resistor, 200kÙ, 1/10W, 5%, 0603 1 Murata/TDK 25 R12,R13 Chip Resistor, 715kÙ, 1/10W, 5%, 0603 2 Murata/TDK 26 R14,R16 Chip Resistor, 49.9kÙ, 1/10W, 5%, 0603 2 Murata/TDK 27 R17 Chip Resistor, 75kÙ, 1/10W, 1%, 0603 1 Murata/TDK 28 R18,R20 Chip Resistor, 100kÙ, 1/10W, 5%, 0603 2 Murata/TDK 29 R21 Chip Resistor, 2.2Ù, 1/10W, 5%, 0603 1 Murata/TDK 30 R23 Chip Resistor, 100Ù, 1/10W, 5%, 0603 1 Murata/TDK 31 R24,R25 Chip Resistor, 22Ù, 1/10W, 5%, 0603, Optional 2 Murata/TDK 32 LED1,LED2, LED3,LED4 LED, 0603, Blue 4 LED Manu 33 PB Push Button Switch 1 Nikkai Omron 34 USB 10.2*14.6*7mm, 4P 1 35 Micro-USB MICRO USB 5P/F SMTB 1 36 U1 IC, ACT2802, T-QFN 44-24 1 Active-Semi, Inc. www.active-semi.com - - ACT 4 ACT2802: Dedicated 5V/2.1A Power Bank Solution 4 PCB LAYOUT *C3 should be placed close to VIN and PGND; C2 must be placed across VOUT and PGND pins 5 FUNCTIONAL TEST 5.1 Battery Charge V/I Profile Battery charge V/I profile Charge current（mA) 2500 2000 1500 1000 500 0 0 1 2 3 Battery voltage（V） 4 5 5.2 Power Path Function Input current(mA) Output current(mA) Charge current(mA) 1513 1620 1728 1942 2135 2152 2167 2184 2200 2216 2232 2247 2256 2267 0 100 200 400 600 800 1000 1200 1400 1600 1800 2000 2100 2270 1912 1912 1911 1910 1884 1671 1445 1227 1002 775 543 316 194 0 (Test condition: Vin=5V, Vbat=3.7V, input current limit=2.5A, fast charge current=2.0A) Active-Semi, Inc. www.active-semi.com - - 5 ACT2802: Dedicated 5V/2.1A Power Bank Solution 2500 Current(mA) 2000 1500 Input Current Output Current 1000 Charge Current 500 0 1 2 3 4 5 6 7 8 9 10 Measuring Points 11 12 13 14 15 5.3 Charge Efficiency (Vin=5V and charge current set at 2000mA) Battery voltage (V) 3.0 3.2 3.7 4.1 Efficiency (%) 90.65 90.91 91.44 91.65 Active-Semi, Semi, Inc. www.active-semi.com - - 6 ACT2802: Dedicated 5V/2.1A Power Bank Solution 5.4 Boost Output Regulation Battery Output Voltage Output Voltage at Load Voltage at 2.1A Output No Load Regulation (V) (V) (V) (%) 3.2 4.98 5.02 0.80 3.7 4.98 5.02 0.80 4.1 4.98 5.02 0.80 5.5 Boost Efficiency and Power Loss (Ta=25℃) Efficiency (%) Vbat Io=100mA Io=500mA Io=1000mA Io=1500mA Io=2100mA 3.2V 93.35 94.22 93.55 91.31 87.91 3.7V 95.09 95.09 94.84 93.23 90.75 4.1V 96.50 96.00 95.57 94.45 92.50 (Note: bigger inductor size can improve efficiency further) Boost converter efficency 100 95 Efficiency(%) 90 85 80 75 Vbat=3.2V 70 Vbat=3.7V 65 Vbat=4.1V 60 10 100 1000 10000 Output current(mA) Active-Semi, Inc. www.active-semi.com - - 7 ACT2802: Dedicated 5V/2.1A Power Bank Solution Boost converter Power Loss 1.6 Power Loss (W) 1.4 1.2 1.0 0.8 0.6 Vbat=3.2V 0.4 Vbat=3.7V 0.2 Vbat=4.1V 0.0 0 500 1000 1500 2000 2500 Output current(mA) 5.6 Boost Standby Power (Ta=25℃) Battery Voltage(V) 3.2 3.7 4.1 Boost Standby Current(mA) 0.54 0.52 0.52 Boost Standby Power(mW) 1.73 1.92 2.18 5.7 Boost Constant Current and Constant Voltage Regulation (Ta=25℃) Vbat=3.2V CC Load CV Load Active-Semi, Inc. www.active-semi.com Vbat=3.7V Vbat=4.1V Vout(V) Iout(mA) Vout (V) Iout(mA) Vout(V) Iout(mA) 5.024 0 5.027 0 5.029 0 5.011 500 5.011 500 5.011 500 5.004 1000 5.001 1000 5.000 1000 4.989 2100 4.984 2100 4.982 2100 4.8 2355 4.8 2374 4.8 2394 4.75 2354 4.75 2373 4.75 2393 4.7 2353 4.7 2373 4.7 2393 4.65 2355 4.65 2373 4.65 2394 4.6 2355 4.6 2375 4.6 2394 4.55 2356 4.55 2374 4.55 2394 - - 8 ACT2802: Dedicated 5V/2.1A Power Bank Solution 4.5 2357 4.5 2377 4.5 2395 4.45 2358 4.45 2378 4.45 2396 4.4 2360 4.4 2377 4.4 2396 4.35 2361 4.35 2380 4.35 2397 4.3 2362 4.3 2380 4.3 2397 4.25 2362 4.25 2381 4.25 2397 4.2 2363 4.2 2382 4.2 2398 4.15 2364 4.15 2385 4.15 2400 4.08 0 4.08 0 4.08 0 Boost Output V/I Profile 5.5 Output voltage(V) 5.0 4.5 4.0 Vbat=3.2V 3.5 Vbat=3.7V Vbat=4.1V 3.0 0 500 1000 1500 2000 2500 Output current(mA) 5.8 Battery Leakage Current in HZ Mode Battery Input Current Power Loss (µA) (µW) Vbat=2.8V 5.1 14.3 Vbat=3.2V 5.8 18.6 Vbat=3.7V 6.4 23.7 Vbat=4.2V 7.2 30.2 Test Conditions Active-Semi, Inc. www.active-semi.com - - 9 ACT2802: Dedicated 5V/2.1A Power Bank Solution 5.9 Ripple and Noise (Ripple Ripple & noise are measured by using 20MHz bandwidth limited oscilloscope) oscilloscope Test Output Ripple at 1A Load Output Ripple at 2.1A 1A Load Conditions (mV) (mV) Vbat=3.2V 20 64.8 Vbat=3.7V 16.8 49.6 Vbat=4.1V 15.2 39.2 5.10 Load Dynamic Response Load oad Step (Vbat=3.7V) 80mA-1000mA-80mA 80mA load step 1000mA-2100mA-100 1000mA load step 5.11 LED Indication Boost or HZ Mode Charge Mode PB time>100ms LED LED1 LED2 LED3 LED4 LED1 LED2 LED3 LED4 VBAT<2.9V Flash Off Off Off Off Off Off Off 2.9V≤VBAT<LED1 Flash Off Off Off Flash Off Off Off LED1≤VBAT<LED2 On Flash Off Off On Off Off Off LED2≤VBAT<LED3 On On Flash Off On On Off Off LED3≤VBAT<LED4 On On On Flash On On On Off VBAT≥LED4 On On On Flash On On On On On On On On On On On On VBAT≥LED4 (End of Charge) Active-Semi, Semi, Inc. www.active-semi.com - - 10 ACT2802: Dedicated 5V/2.1A Power Bank Solution 5.12 System Management V IN HZ: 1 >0 o PB is press r HZ=0 an ed fo r 100 d ms ACT2802 System Operation Flow Chart Inv lid Va V IN d ali d an =1 HZ 5.13 Key Components Temperature Test (Ta=40℃, burning for 2 hours) Charge mode, 2.0A charge current Vin(V) IC(℃) Inductor(℃) PCB(℃) Vbat(V) 5.0 68 60.2 52 3.2 5.0 69 62.1 54 3.7 5.0 68.2 61.6 53.7 4.1 Boost mode, 2.1A output current Active-Semi, Inc. www.active-semi.com Vbat(V) IC(℃) Inductor(℃) PCB(℃) Vout(V) 3.2 87.5 86.5 78.2 5.0 3.7 74.2 76.8 68.6 5.0 4.1 65.3 68.6 62.4 5.0 - - 11 ACT2802: Dedicated 5V/2.1A Power Bank Solution 6 PCB LAYOUT GUIDANCE The following guideline is base on the schematic in Section 2. 1) Arrange the power components to reduce the AC loop size that consists of C2, VOUT, SW and PGND. C2 (1206 size) must be placed close to the IC and across the VOUT and PGND traces and SW trace goes under the C2 as shown in the following layout figure. 2) Use copper plane for PGND for best heat dissipation and noise immunity. AGND and PGND are connected under the IC thermal pad with 4x4 vias matrix. 3) SW copper area should be limited due to EMI consideration. 4) Use Kevin sense from sense resistor R2 and R2A to CSP and CSN pins as shown in the layout figure. 5) A separate trace is from VBAT input to BAT pin for battery voltage sense accuracy. 6) RC snubber is recommended to add across SW to PGND to reduce EMI noise. 7) A 20V/3.0A schottky is added from inductor terminal to VOUT to reduce EMI noise. Active-Semi, Inc. www.active-semi.com - - 12 ACT2802: Dedicated 5V/2.1A Power Bank Solution Top Layer Bottom Layer Active-Semi, Semi, Inc. www.active-semi.com - - 13 ACT2802: Dedicated 5V/2.1A Power Bank Solution 7 EMI TEST Vbat=4.1V, Output : 5V/2A Horizontal Active-Semi, Inc. www.active-semi.com - - 14 ACT2802: Dedicated 5V/2.1A Power Bank Solution Vbat=4.1V, Output : 5V/2A Vertical Active-Semi, Inc. www.active-semi.com - - 15