DA6011B.001 18 October, 2011 MAS6011B Solar Cell Energy Harvesting System Manager VDD • • • • MAS6011 XPD LB Ultra Low Power, 110nA Low Battery Indicator Precise Power Up/Down Battery Overcharging Protection SW SOL GND DESCRIPTION The MAS6011 solar cell system manager monitors the supply voltage and charging of a batterypowered system containing a small solar cell. The current consumption of this IC is extremely low, 110 nA, which means the system can charge from very low light conditions and also stay in power down mode for years and still operate directly from the battery before recharging. To be able to charge a battery also in condition with very limited light, a large solar cell is usually used. This can on the other hand easily destroy the battery due to over voltage during strong sun light. MAS6011 solves this dilemma and will give secure FEATURES • • • • • • • Ultra Low Current Consumption, typ 110nA Low Supply Voltage Operation, min 2.0V Battery Overcharging Protection Power On Indicator and secure Power ON after shut down Deep discharge protection of battery during shut down mode Precise Shut Down and precise Low Battery warning threshold levels Suitable for rechargeable 3V Lithium Vanadium Pentoxide (VL-type) batteries protection of a secondary 3V battery over a big range of light strengths (lx). Three output signals indicate the state of the system. Power Down (XPD) indicates whether the supply voltage is high enough to power up and run the system. Low Battery (LB) is used to signal the condition when the battery capacity is low and when to move to power saving mode. The third signal, SOL, is used for battery charging control. When the battery is full it bypasses the charging current by an internal shunt switch to avoid overcharging. The SW pin can also be used to control an external shunt switch for higher currents. APPLICATIONS • • • • • • • Solar Powered Watch Solar Powered Wireless Sensor Solar Powered Devices with Back-Up GPS Modules Time Code Receiver modules Electronic locks Energy Harvesting 1 (10) DA6011B.001 18 October, 2011 FUNCTIONAL DESCRIPTION The solar manager generates three main signals: XPD (Power Down), LB (Low Battery) and SOL (Solar Charging). The fourth SW signal is for controlling an optional external PMOS transistor. These signals are produced by three comparators which have hysteresis build in. Each comparator compares the supply voltage (VDD) to the internal switching levels. The current consumption of the comparators is extremely low. The electrical parameters are described more detailed in the Electrical Characteristics chapter. The XPD signal can be used to power down the whole system whenever the supply voltage level has dropped too low (see application figure 4). When the supply voltage is too low the XPD goes low to power down the solar powered system. When the supply voltage is high enough the XPD goes high controlling power up condition. For a low power system (max current consumption 1mA) the XPD pin output can be used as a system supply voltage (see application figure 5) to keep the systems current consumption to a minimum. The LB signal indicates that the battery is low but not empty. It can be used to control the system into a power saving mode. In power on (XPD=high) LB goes high when supply voltage level is too low and LB goes low when supply voltage level is high enough. In power down (XPD=low) the LB is low. SOL is used for controlling the charging of the rechargeable battery. Normally the internal PMOS switch between VDD and the SOL pin is non- conductive but when the power supply voltage rises too much this switch is switched on to shunt the solar cell charging current and to prevent battery overcharging. The maximum shunt current capability of the internal PMOS switch is typically 28 mA. If a larger shunt current is needed an external PMOS transistor can be used controlled by the SW pin (see application figure 6). In operation without an external Schottky diode between the pins SOL and GND, the voltage at pin SOL is clamped to about 700 mV below GND by an internal diode-connected NPN transistor. MAS6011 does not have any control pin. After the power supply is connected the device is ready to be used. The XPD, LB and SOL/SW switching levels have been designed for usage with VL-type rechargeable lithium vanadium pentoxide batteries. Those batteries are compact, high energy secondary batteries that have nearly twice the energy of conventional button-shaped Ni-Cd batteries. The self discharge rate is less than 2% a year which makes them very useful as a power source in systems that might be stored for a long time without re-charging. Figure 1 illustrates the MAS6011 functions and shows the comparator switching levels for both battery charging (rising VDD) and discharging (falling VDD) conditions. 2 (10) DA6011B.001 18 October, 2011 FUNCTIONAL DESCRIPTION VDD 3.3V SOL_OFF (charging off) 3.2V SOL_ON (charging on) 3.1V 3.0V BATTERY CHARGING (VDD RISING) BATTERY DISCHARGING (VDD FALLING) 2.9V Battery Voltage 2.8V 2.7V 2.6V LB_OFF (LB=low) XPD_OFF (XPD=high) LB_ON (LB=high) 2.5V 2.4V XPD_ON (XPD=low) 2.3V 2.2V 2.1V 2.0V SOL LB XPD SW Figure 1. MAS6011 functions 3 (10) DA6011B.001 18 October, 2011 ABSOLUTE MAXIMUM RATINGS All voltages with respect to ground. Parameter Supply Voltage Voltage range for all pins Operating temperature Storage Temperature Symbol Conditions VDD TA TS Min Max Unit -0.3 -0.3 -40 -50 5.5 VDD+0.3 +85 +125 V V o C o C Stresses beyond those listed may cause permanent damage to the device. The device may not operate under these conditions, but it will not be destroyed. This is a CMOS device and therefore it should be handled carefully to avoid any damage by electrostatic voltages (ESD). The most sensitive pin for the ESD is the SOL pin. ELECTRICAL CHARACTERISTICS: MAS6011BA1 (3V BATTERY, MCU VDDmin ≤ 2.1V) Operating Conditions: TA = -40°C to +85°C, typical values at TA = +27°C, unless otherwise specified. Parameter Supply voltage Symbol VDD Current consumption IDD XPD switching level XPD_OFF XPD_ON VXPD(H) XPD hysteresis XPD output voltage VXPD(OUT) LB switching level LB hysteresis LB_OFF LB_ON VLB(H) LB output voltage VLB(OUT) SOL switching level SOL hysteresis SOL sink current Conditions SOL_OFF SOL_ON VSOL(H) ISOL SOL leakage current VDD=2V VDD=3V VDD=3.5V Power Down Off (XPD high) Power Down On (XPD low) VDD = 2.1 V, IXPD = -1mA Low Battery Off (LB low) Low Battery On (LB high) LB high, ILB = -50 µA LB low, ILB = +50 µA Solar Charging Off Solar Charging On VDD = 3.6 V, SOL = 0 V, SOL switch On VDD = 2.9 V Min Typ Max Unit 2.0 3.0 3.6 V 30 50 60 2.40 2.10 180 85 110 130 2.60 2.30 300 160 200 230 2.80 2.50 600 nA 2.0 2.55 2.35 100 V mV V 2.70 2.50 200 2.85 2.65 400 3.02 2.90 50 3.30 3.15 150 0.05 3.55 3.40 300 mV 19 28 43 mA 50 nA VDD-0.05 V mV V -50 V LB_OFF – XPD_OFF VLB_XPD_OFF 10 100 200 mV LB_ON – XPD_ON VLB_XPD ON 100 200 300 mV SOL_OFF – LB_OFF VSOL_LB_OFF 200 600 800 mV SOL_ON – LB_ON VSOL_LB ON 350 650 949 mV TBD = To be defined 4 (10) DA6011B.001 18 October, 2011 ELECTRICAL CHARACTERISTICS: MAS6011BA1 (3V BATTERY, MCU VDDmin ≤ 2.1V) 200 180 160 IDD [nA] 140 120 100 VDD=3.5V 80 VDD=3.0V 60 VDD=2.0V 40 20 0 ‐50 0 50 100 Temperature [°C] Figure 2. Typical temperature dependency of IDD Figure 3. Typical temperature dependency of comparator switching levels 5 (10) DA6011B.001 18 October, 2011 TYPICAL APPLICATION VDD MAS6011 XPD Solar cells 4.7 µF LB POWER DOWN VDD SOLAR POWERED SYSTEM GND V BATT 3V + – SW GND SOL Schottky diode: Vishay SD103A or similar. Figure 4. Typical application circuit of MAS6011BA1 – XPD for power down control of solar powered system VDD MAS6011 XPD Solar cells 4.7 µF LB VDD V BATT 3V MCU – GND SW SOL + GND Schottky diode: Vishay SD103A or similar. Figure 5. Typical application circuit of MAS6011BA1 – XPD as supply voltage for a low power microcontroller 6 (10) DA6011B.001 18 October, 2011 TYPICAL APPLICATION VDD 4.7 µF MAS6011 Solar cells XPD LB VDD V BATT 3V MCU PMOS SOL – GND SW Schottky diode: Vishay SD103A or similar. + GND Figure 6. Typical application circuit of MAS6011BA1 – external PMOS transistor shunt for solar current Figure 7. Typical application – Wireless sensor system with Time Code Reception The system in figure 7 shows a wireless module that can receive both the AM long wave Time Code Signal as well as measuring different physical parameters via several sensors. The information is transmitted via a low power RF transmitter to a receiver indoors. By placing the module where the Time Code signal is strong good reception can be accomplished also in buildings normally blocking this signal. The low power consumption of the MAS6011 together with the energy harvesting solar cell enables this system to operate without the need for battery replacement. 7 (10) DA6011B.001 18 October, 2011 MAS6011BA1 IN QFN 3x3 PACKAGE QFN 3x3 6ld GND SW XPD 6 5 4 1234 GBA1 YWW 1 2 3 SOL VDD LB Top Marking Information: 1234 = Product Number, BA1 = Version Number G = Lead Free, RoHS Compliant Package, YWW = Year Week QFN 3x3 PIN DESCRIPTION Pin Name Pin Type SOL VDD LB XPD SW GND 1 2 3 4 5 6 AO P DO DO DO G Function Solar Charging Output Positive Power Supply Low Battery Output Power Down Output External Switch Control Output Power Supply Ground NC = Not Connected, P = Power, G = Ground, DO = Digital Output, AO = Analog Output 8 (10) DA6011B.001 18 October, 2011 PACKAGE (QFN 3X3x0.75 6ld) OUTLINE D D/2 E/2 TOP VIEW A3 A PIN 1 MARK AREA SIDE VIEW A1 SEATING PLANE D2 D2/2 L E2 E2/2 SHAPE OF PIN #1 IDENTIFICATION IS OPTIONAL BOTTOM VIEW EXPOSED PAD e Symbol Min b Nom Max PACKAGE DIMENSIONS A 0.70 0.75 0.80 A1 0.0 0.02 0.05 A3 0.178 0.203 0.228 b 0.350 0.400 0.450 D 3.00 BSC D2 (Exposed pad) 2.25 2.3 2.35 E 3.00 BSC E2 (Exposed pad) 1.45 1.5 1.55 e 0.95 BSC L 0.425 0.475 0.525 Dimensions do not include mold or interlead flash, protrusions or gate burrs. Unit mm mm mm mm mm mm mm mm mm mm 9 (10) DA6011B.001 18 October, 2011 ORDERING INFORMATION Product Code MAS6011BA1WA305 MAS6011BA1Q1306 Product Package Solar Cell System Manager (for 3 V rechargeable battery) Solar Cell System Manager (for 3 V rechargeable battery) 400 μm thick dies on tray QFN 3x3x0.75mm Pb-free RoHS compliant Comments Tape and Reel LOCAL DISTRIBUTOR MICRO ANALOG SYSTEMS OY CONTACTS Micro Analog Systems Oy Kutomotie 16 FI-00380 Helsinki, FINLAND Tel. +358 10 835 1100 Fax +358 10 835 1109 http://www.mas-oy.com 10 (10)