da6011b.001 18 october, 2011 1 (10) MAS6011B solar cell energy harvesting system manager ? ultra low power, 110na ? low battery indicator ? precise power up/down ? battery overcharging protection description the mas6011 solar cell system manager monitors the supply voltage and charging of a battery- powered 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 operat e 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 protection of a secondary 3v battery over a big range of light strengths (lx). three output signals indica te 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. features applications ? 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 ? solar powered watch ? solar powered wireless sensor ? solar powered devices with back-up ? gps modules ? time code receiver modules ? electronic locks ? energy harvesting xpd vdd sol gnd mas6011 lb sw
da6011b.001 18 october, 2011 2 (10) 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 (m ax 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 c ontrol 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 stor ed 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.
da6011b.001 18 october, 2011 3 (10) functional description 2.0v 2.5v 3.0v 3.2v 3.1v 2.7v 2.9v 2.8v 2.6v 2.2v 2.4v 2.3v 2.1v 3.3v battery voltage vdd sol_off (charging off) sol_on (charging on) lb_off (lb=low) lb_on (lb=high) xpd_off (xpd=high) xpd_on (xpd=low) battery charging (vdd rising) battery discharging (vdd falling) sol lb xpd sw figure 1. mas6011 functions
da6011b.001 18 october, 2011 4 (10) absolute maximum ratings all voltages with respect to ground. parameter symbol conditions min max unit supply voltage vdd -0.3 5.5 v voltage range for all pins -0.3 vdd+0.3 v operating temperature t a -40 +85 o c storage temperature t s -50 +125 o c stresses beyond those listed may cause permanent damage to the dev ice. the device may not operat e under these conditions, but i t will not be destroyed. this is a cmos device and therefore it s hould be handled carefully to avoid any damage by electrostatic voltages (esd). the mos t sensitive pin for the esd is the sol pin. electrical characteristics: MAS6011Ba1 (3v battery, mcu vdd min 2.1v) operating conditions: t a = -40c to +85c, typical values at t a = +27c, unless otherwise specified. parameter symbol conditions min typ max unit supply voltage vdd 2.0 3.0 3.6 v current consumption i dd vdd=2v vdd=3v vdd=3.5v 30 50 60 85 110 130 160 200 230 na xpd switching level xpd_off xpd_on power down off (xpd high) power down on (xpd low) 2.40 2.10 2.60 2.30 2.80 2.50 v xpd hysteresis v xpd(h) 180 300 600 mv xpd output voltage v xpd(out) vdd = 2.1 v, i xpd = -1ma 2.0 v lb switching level lb_off lb_on low battery off (lb low) low battery on (lb high) 2.55 2.35 2.70 2.50 2.85 2.65 v lb hysteresis v lb(h) 100 200 400 mv lb output voltage v lb(out) lb high, i lb = -50 a lb low, i lb = +50 a vdd-0.05 0.05 v sol switching level sol_off sol_on solar charging off solar charging on 3.02 2.90 3.30 3.15 3.55 3.40 v sol hysteresis v sol(h) 50 150 300 mv sol sink current i sol vdd = 3.6 v, sol = 0 v, sol switch on 19 28 43 ma sol leakage current vdd = 2.9 v -50 50 na lb_off ? xpd_off v lb_xpd_off 10 100 200 mv lb_on ? xpd_on v lb_xpd on 100 200 300 mv sol_off ? lb_off v sol_lb_off 200 600 800 mv sol_on ? lb_on v sol_lb on 350 650 949 mv tbd = to be defined
da6011b.001 18 october, 2011 5 (10) electrical characteristics: MAS6011Ba1 (3v battery, mcu vdd min 2.1v) 0 20 40 60 80 100 120 140 160 180 200 \ 50 0 50 100 idd ? [na] temperature ? [c] ? vdd=3.5v vdd=3.0v vdd=2.0v figure 2. typical temperature dependency of idd figure 3. typical temperature dependency of comparator switching levels
da6011b.001 18 october, 2011 6 (10) typical application 4.7 f solar cells + ? v batt 3 v solar powered system schottky diode: vishay sd103a or similar. vdd gnd power down xpd vdd sol gnd mas6011 lb sw figure 4. typical application circuit of MAS6011Ba1 ? xpd for power down control of solar powered system 4.7 f solar cells + ? v batt 3 v mcu schottky diode: vishay sd103a or similar. vdd gnd xpd vdd sol gnd mas6011 lb sw figure 5. typical application circuit of MAS6011Ba1 ? xpd as supply voltage for a low power microcontroller
da6011b.001 18 october, 2011 7 (10) typical application 4.7 f solar cells + ? v batt 3 v mcu schottky diode: vishay sd103a or similar. vdd gnd xpd vdd sol gnd mas6011 lb sw pmos figure 6. typical application circuit of MAS6011Ba1 ? exte rnal 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 c an receive both the am long wave time code signal as well as measuring different physical parameters via seve ral sensors. the information is transmitted via a low power rf transmitter to a receiver indoors. by plac ing 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 sy stem to operate without the need for battery replacement.
da6011b.001 18 october, 2011 8 (10) MAS6011Ba1 in qfn 3x3 package 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 function sol 1 ao solar charging output vdd 2 p positive power supply lb 3 do low battery output xpd 4 do power down output sw 5 do external switch control output gnd 6 g power supply ground nc = not connected, p = power, g = ground, do = digital output, ao = analog output qfn 3x3 6ld sol gnd lb vdd xpd 4 1 1234 gba1 yww 23 5 6 sw
da6011b.001 18 october, 2011 9 (10) d/2 e / 2 seating plane a 1 side view top view d 2 d 2 / 2 e 2 / 2 e 2 l b bottom view d e a 3 pin 1 mark area a exposed pad shape of pin #1 identification is optional package (qfn 3x3x0.75 6ld) outline symbol min nom max unit package dimensions a 0.70 0.75 0.80 mm a1 0.0 0.02 0.05 mm a3 0.178 0.203 0.228 mm b 0.350 0.400 0.450 mm d 3.00 bsc mm d2 (exposed pad) 2.25 2.3 2.35 mm e 3.00 bsc mm e2 (exposed pad) 1.45 1.5 1.55 mm e 0.95 bsc mm l 0.425 0.475 0.525 mm dimensions do not include mold or inte rlead flash, protrusions or gate burrs.
da6011b.001 18 october, 2011 10 (10) ordering information product code product package comments MAS6011Ba1wa305 solar cell system manager (for 3 v rechargeable battery) 400 m thick dies on tray MAS6011Ba1q1306 solar cell system manager (for 3 v rechargeable battery) qfn 3x3x0.75mm pb-free rohs compliant 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
|
