LP8720 One Step-Down DC/DC and Five Linear Regulators with I2C Compatible Interface General Description Features The LP8720 is a multi-function, programmable Power Management Unit, optimized for sub block power requirement solution. This device integrates one highly efficient 400 mA step-down DC/DC converter with Dynamic Voltage Scale (DVS), five low noise low dropout (LDO) voltage regulators and a 400 KHz I2C-compatible interface to allow a host controller access to the internal control registers of the LP8720. The LP8720 additionally features programmable power-on sequencing. LDO regulators provide high PSRR and low noise ideally suited for supplying power to both analog and digital loads. The package will be the smallest 2.5 mm x 2.0 mm micro SMD 20–bump package. ■ 5 Low Noise LDO’s for up to 300 mA ■ One high-efficiency Synchronous Magnetic Buck Regulator, IOUT 400 mA High efficiency PFM mode @low IOUT Auto Mode PFM/PWM switch Low inductance 2.2 µH @ 2 MHz clock Dynamic Voltage Scale control ■ I2C-compatible interface for the controlling of internal registers ■ 20–bump 2.5 x 2.0 mm micro SMD package Key Specifications ■ ■ ■ ■ Applications ■ Cellular Handsets ■ Portable hand-held products Programmable Vout from 0.8V to 2.3V on DC/DC Automatic soft start on DC/DC 200 mV typ Dropout Voltage at 300 mA on LDO’s 2% (typ) Output Voltage accuracy on LDO’s Typical Application Diagram 30067501 © 2009 National Semiconductor Corporation 300675 www.national.com LP8720 One Step-Down DC/DC and Five Linear Regulators with I2C Compatible Interface November 30, 2009 LP8720 Device Pin Diagram (Micro SMD 20) TOP VIEW 30067502 Package Marking Information 30067503 Ordering Information Order Number Package Type Product Identification Supplied as LP8720TLE micro SMD 8720 250 Tape & Reel LP8720TLX micro SMD 8720 3000 Tape & Reel Upon request there will be available custom versions – customer can order own default voltages and own startup sequence. For more information please contact local National Semiconductor Corp. sales office. www.national.com 2 LP8720 LP8720 Pin Descriptions Pin Number Name Type A4 VBATT P Description Battery Input for LDO1 and all internal circuitry. E4 VINB P Battery Input for Buck. A2 VIN1 P Battery Input for LDO2 and LDO3. D1 VIN2 P Battery Input for LDO4 and LDO5. B4 LDO1 A LDO1 Output. A3 LDO2 A LDO2 Output. A1 LDO3 A LDO3 Output. C1 LDO4 A LDO4 Output. E1 LDO5 A LDO5 Output. E3 SW A Buck Output. D2 FB A Buck Feedback. D4 GNDB G Power Ground for Buck. B1 GND G IC Ground. C4 SDA DI/O I2C-compatible Serial Interface Data Input/Output. Open Drain output, external pull up resistor is needed, typ 1.5 kΩ. If not in use then hard wire to GND. C3 SCL DI I2C-compatible Serial Interface Clock input. External pull up resistor is needed, typ 1.5 kΩ. If not in use then hard wire to GND. B3 IRQ_N DO Interrupt output, active LOW. Open Drain output, external pull up resistor is needed, typ 10 kΩ. If not in use then hard wire to GND or leave floating. E2 EN DI Enable. EN=LO standby. EN=HI power on. Internal pull down resistor 500 kΩ. If not in use then hard wire to VBATT. B2 DEFSEL DI Control input that sets the default voltages and startup sequence. Must be hard wired to BATT or GND or left floating (Hi-Z) for specific application. When DEFSEL= VBATT then setup 1 is used for default voltages and startup sequence. When DEFSEL= GND then setup 2 is used for default voltages and startup sequence. When DEFSEL= floating (Hi-Z) setup 3 is used for default voltages and startup sequence. C2 IDSEL DI Control input that sets the slave address for serial interface. Must be hard wired to BATT or GND or left floating (Hi-Z) for specific application. When IDSEL= VBATT then slave address is 7h’7F When IDSEL= floating (Hi-Z) then slave address is 7h’7C When IDSEL= GND then slave address is 7h’7D D3 DVS DI Dynamical Voltage Scaling. When DVS=HI then Buck voltage set BUCK_V1 is in use. When DVS=LO then Buck voltage set BUCK_V2 is in use. Buck voltage set BUCK_V1 should be higher than Buck voltage set BUCK_V2. If not in use then hard wire to VBATT or GND. A: D I DI/O G O P Analog Pin Digital Pin Input Pin Digital Input/Output Pin Ground Output Pin Power Connection 3 www.national.com LP8720 Device Description OPERATION MODES POWER-ON-RESET: After VBATT gets above POR higher threshold DEFSEL-pin and IDSEL-pin are read. Then all internal registers of LP8720 are reset to the default values and after that LP8720 goes to STANDBY mode. This process duration max is 500 µs. STANDBY: In STANDBY mode only serial interface is working and all other PMU functions are disabled – PMU is in low power condition. In STANDBY mode LP8720 can be (re)configured via Serial Interface. START UP: START UP sequence is defined by registers contents. START UP sequence starts: 1) If rising edge on EN-pin. 2) After cooling down from thermal shutdown event if EN=HI. It is not recommended to write to LP8720 registers during START UP. If doing so then current START UP sequence may become undefined. IDLE: PMU will enter into IDLE mode (normal operating mode) after end of START UP sequence. In IDLE mode all LDO’s and BUCK can be enabled/disabled via Serial Interface. Also in IDLE mode LP8720 can be (re) configured via Serial Interface. SHUT DOWN: SHUT DOWN sequence is “reverse order of start up sequence” and this is defined by registers contents. SHUT DOWN starts 1) If falling edge on EN-pin. 2) If temperature exceeds thermal shutdown threshold TSD +160°C. It is not recommended to write to LP8720 registers during SHUT DOWN. If doing so then current SHUT DOWN sequence may become undefined. 30067504 Additional Functions SLEEP: If sum of all LDO’s load currents and BUCK load current is no higher than 5mA then user can put PMU to SLEEP. In SLEEP PMU GND current is minimized. In SLEEP LDO’s and BUCK cannot be loaded with big current. There are 2 possibilities to use SLEEP: 1) Control via Serial Interface. 2) Control by DVS-pin. DVS: Dynamic Voltage Scaling allows using 2 voltage sets for BUCK. There are 2 possibilities to use DVS: 1) Control via Serial Interface. 2) Control by DVS-pin. INTERRUPT: If interrupt is not masked then PMU forces IRQ_N low if temperature crossed TSD_EW limit (thermal shutdown early warning) or/and thermal shutdown event took place. IRQ_N is released by reading Interrupt register. www.national.com 4 LP8720 POWER-ON AND POWER-OFF SEQUENCES Start Up Sequence if DEFSEL=VBATT or DEFSEL=Hi-Z 30067505 tBON 150 µs – Reference and bias turn ON. Min 100 µs max 200 µs. tS 25 µs – time step. Time step accuracy is defined by OSC frequency accuracy. Note 1 START UP and SHUT DOWN sequences are defined by registers. Sequences given here are valid if there the registers are not rewritten via Serial Interface. Note 2 The timing showed here define time points when LDO’s and BUCK are enabled/disabled. Enabling /disabling process duration depends on loading conditions. Buck startup duration is 140 µs for no load. LDO startup duration is no more than 35 µs. For details please see LDO’s and BUCK electrical specifications. Note 3 LDO5 and BUCK are disabled. If LDO5 and/or BUCK are enabled via Serial Interface and startup sequence is not changed via Serial interface, then LDO5 and BUCK are disabled with no delay from falling edge on EN-pin. Note 4 At this time point registers 0x09 and 0x0C are reset to POR default values. Note 5 At this time point registers 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 and 0x08 are reset to POR default values. 5 www.national.com LP8720 Start Up Sequence if DEFSEL=GND 30067506 tBON 150 µs – Reference and bias turn ON. Min 100 µs max 200 µs. tS 25 µs – time step. Time step accuracy is defined by OSC frequency accuracy. Note 1 START UP and SHUT DOWN sequences are defined by registers. Sequences given here are valid if there the registers are not rewritten via Serial Interface. Note 2 The timing showed here define time points when LDO’s and BUCK are enabled/disabled. Enabling /disabling process duration depends on loading conditions. Buck startup duration is 140 µs for no load. LDO startup duration is no more than 35 µs. For details please see LDO’s and BUCK electrical specifications. Note 3 LDO1, LDO2, LDO4, LDO5 and BUCK are disabled. If LDO1, LDO2, LDO4, LDO5 and/or BUCK are enabled via Serial Interface and startup sequence is not changed via Serial interface, then LDO1, LDO2, LDO4, LDO5 and BUCK are disabled with no delay from falling edge on EN-pin. Note 4 At this time point registers 0x09 and 0x0C are reset to POR default values. Note 5 At this time point registers 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 and 0x08 are reset to POR default values. www.national.com 6 LP8720 Start Up Sequence DEFSEL Start Up Sequence Shut Down Sequence LDO1, 2, 3, 4 enable same time. LDO5 and BUCK enable via Serial Interface. In reverse order of start up sequence. GND LDO3 enable. LDO1, 2, 4, 5 and BUCK enable via Serial Interface . In reverse order of start up sequence. Hi-Z LDO1, 2, 3, 4 enable same time. LDO5 and BUCK enable via Serial Interface. In reverse order of start up sequence. VBATT Default Output Voltages Output Max Current [mA] Default output Voltage [V] and default ON/OFF if EN=HI DEFSEL=VBATT DEFSEL=GND DEFSEL=Hi-Z LDO1 300 3.0 ON 3.0 OFF 2.8 ON LDO2 300 2.6 ON 3.0 OFF 2.6 ON LDO3 300 1.8 ON 2.6 ON 1.8 ON LDO4 300 1.0 ON 2.6 OFF 1.2 ON LDO5 300 3.3 OFF 3.3 OFF 3.3 OFF BUCK 400 1.0 OFF 1.2/1.31) OFF 1.2 OFF Note 1) BUCK voltage is 1.2V if DVS=LO and 1.3V if DVS=HI. 7 www.national.com www.national.com 8 LDO4_ T[2] LDO5_ T[2] LDO4_ SETTINGS LDO5_ SETTINGS 0x04 0x05 TSD TSD_ INT TSD_ MASK APU_ TSD PULLDOWN_ BITS STATUS_ BITS INTERRUPT_ BITS *) INTERRUPT_ MASK *) 0x0A 0x0B 0x0C LDO3_ EN *) Registers STATUS_BITS 0x0A and INTERRUPT_BITS 0x0B are read only. BUCK_ LDO5_ LDO4_ LDO3_ PULLDOWN PULLDOWN PULLDOWN PULLDOWN LDO4_ EN LDO2_ PULLDOWN LDO2_ EN BUCK_ V2[1] 0x09 LDO5_ EN BUCK_ V2[2] BUCK_ EN SLEEP_ MODE BUCK_ V2[3] DVS_ V2/V1 BUCK_ V2[4] ENABLE_ BITS BUCK_ V1[1] LDO5_ V[1] LDO4_ V[1] LDO3_ V[1] 0x08 BUCK_ V1[2] LDO5_ V[2] LDO4_ V[2] LDO3_ V[2] FORCE_ PWM BUCK_ V1[3] LDO5_ V[3] LDO4_ V[3] LDO3_ V[3] LDO2_ V[1] BUCK_ SETTINGS2 BUCK_ V1[4] LDO5_ V[4] LDO4_ V[4] LDO3_ V[4] LDO2_ V[3] 0x07 BUCK_ T[0] LDO5_ T[0] LDO4_ T[0] LDO3_ T[0] LDO2_ V[4] BUCK_ SETTINGS1 BUCK_ T[1] LDO5_ T[1] LDO4_ T[1] LDO3_ T[1] LDO2_ T[0] LDO1_ V[1] EXT_SLEEP_ CONTROL Bit 1 0x06 BUCK_ T[2] LDO3_ T[2] LDO3_ SETTINGS 0x03 LDO2_ T[1] LDO2_ V[2] LDO2_ T[2] LDO1_ V[3] LDO2_ SETTINGS LDO1_ V[4] 0x02 LDO1_ T[0] LDO1_ V[2] LDO1_ T[1] LDO1_ T[2] Bit 2 LDO1_ SETTINGS Bit 3 0x01 Bit 4 0x00 Bit 5 EXT_DVS_ CONTROL Bit 6 GENERAL_ SETTINGS Bit 7 Name Addr When IDSEL= VBATT then slave address is 7h’7F When IDSEL= floating (Hi-Z) then slave address is 7h’7C When IDSEL= GND then slave address is 7h’7D Control Register Map GND Hi-Z 1000 1111 1000 0100 1000 1111 0000 0101 0000 1001 0000 1001 1110 0101 1110 1011 1110 1001 1111 1111 1111 1111 1111 1111 0110 0011 1111 1010 0110 0101 0110 1100 0111 0101 0110 1100 0111 0101 1111 1101 0111 0101 0111 1101 1111 1101 0111 1001 0000 0001 0000 0101 0000 0001 VBATT POR default DEFSEL TSD_EW_ MASK TSD_EW_ INT TSD_EW 0000 0011 0000 0011 0000 0011 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 LDO1_ 0011 1111 0011 1111 0011 1111 PULLDOWN LDO1_ EN BUCK_ V2[0] BUCK_ V1[0] LDO5_ V[0] LDO4_ V[0] LDO3_ V[0] LDO2_ V[0] LDO1_ V[0] SHORT_ TIMESTEP Bit 0 LP8720 LP8720 Register 0x00 EXT_DVS_CONTROL EXT_SLEEP_CONTROL SHORT_TIMESTEP 1 – DVS-pin control: DVS=HI then BUCK_V1[4:0] DVS=LO then BUCK_V2[4:0] 0 – Serial interface control: DVS_V2/V1=1 then BUCK_V1[4:0] DVS_V2/V1=0 then BUCK_V2[4:0] 1 – DVS-pin control: DVS=HI then normal DVS=LO then SLEEP 0 – Serial interface control: SLEEP_MODE=0 then normal SLEEP_MODE=1 then SLEEP 1 – time step tS=25 µs 0 – time step tS=50 µs By request time step 100 µs/200 µs is available. Registers 0x01 – 0x07 LDO1_V[4:0] LDO2_V[4:0] LDO3_V[4:0] LDO5_V[4:0] 00000 – 1.20V 00001 – 1.25V 00010 – 1.30V 00011 – 1.35V 00100 – 1.40V 00101 – 1.45V 00110 – 1.50V 00111 – 1.55V 01000 – 1.60V 01001 – 1.65V 01010 – 1.70V 01011 – 1.75V 01100 – 1.80V 01101 – 1.85V 01110 – 1.90V 01111 – 2.00V 10000 – 2.10V 10001 – 2.20V 10010 – 2.30V 10011 – 2.40V 10100 – 2.50V 10101 – 2.60V 10110 – 2.65V 10111 – 2.70V 11000 – 2.75V 11001 – 2.80V 11010 – 2.85V 11011 – 2.90V 11100 – 2.95V 11101 – 3.00V 11110 – 3.10V 11111 – 3.30V LDO4_V[4:0] 00000 – 0.80V 00001 – 0.85V 00010 – 0.90V 00011 – 1.00V 00100 – 1.10V 00101 – 1.20V 00110 – 1.25V 00111 – 1.30V 01000 – 1.35V 01001 – 1.40V 01010 – 1.45V 01011 – 1.50V 01100 – 1.55V 01101 – 1.60V 01110 – 1.65V 01111 – 1.70V 10000 – 1.75V 10001 – 1.80V 10010 – 1.85V 10011 – 1.90V 10100 – 2.00V 10101 – 2.10V 10110 – 2.20V 10111 – 2.30V 11000 – 2.40V 11001 – 2.50V 11010 – 2.60V 11011 – 2.65V 11100 – 2.70V 11101 – 2.75V 11110 – 2.80V 11111 – 2.85V BUCK_V1[4:0] BUCK_V2[4:0] 0000 External resistor divider 00001 – 0.80V 00010 – 0.85V 00011 – 0.90V 00100 – 0.95V 00101 – 1.00V 00110 – 1.05V 00111 – 1.10V 01000 – 1.15V 01001 – 1.20V 01010 – 1.25V 01011 – 1.30V 01100 – 1.35V 01101 – 1.40V 01110 – 1.45V 01111 – 1.50V 10000 – 1.55V 10001 – 1.60V 10010 – 1.65V 10011 – 1.70V 10100 – 1.75V 10101 – 1.80V 10110 – 1.85V 10111 – 1.90V 11000 – 1.95V 11001 – 2.00V 11010 – 2.05V 11011 – 2.10V 11100 – 2.15V 11101 – 2.20V 11110 – 2.25V 11111 – 2.30V BUCK_V1[4:0] should be higher (or equal) than BUCK_V2[4:0]. LDO1_T[2:0] LDO2_T[2:0] LDO3_T[2:0] LDO4_T[2:0] LDO5_T[2:0] BUCK_T[2:0] 000 – start up delay 0 001 – start up delay = 1 * time step tS 010 – start up delay = 2 * time step tS 011 – start up delay = 3 * time step tS 100 – start up delay = 4 * time step tS 101 – start up delay = 5 * time step tS 110 – start up delay = 6 * time step tS 111 – NO startup FORCE_PWM 1 – Buck is forced to work in PWM mode 0 – Buck works in automatic PFM/PWM selection mode. For proper startup operation “111 NO start up” should have corresponding bit in ENABLE_BITS register 0x08 set to 0 (disable). 9 www.national.com LP8720 Register 0x08 LDO1_EN LDO2_EN LDO3_EN LDO4_EN LDO5_EN BUCK_EN In STANDBY mode 1 – During next START UP sequence will be enabled. 0 – During next START UP sequence will be NOT enabled. For proper operation output having “111 NO start up” should have corresponding enable bit 0 (disable). In IDLE mode the bit has immediate effect. 1 – Enable 0 – Disable SLEEP_MODE 1 – SLEEP 0 – normal This bit has effect only if EXT_SLEEP_CONTROL=0 (register 0x00) DVS_V2/V1 1 – buck voltage is BUCK_V1[4:0] 0 – buck voltage is BUCK_V2[4:0] This bit has effect only if EXT_DVS_CONTROL=0 (register 0x00) Register 0x09 LDO1_PULLDOWN LDO2_PULLDOWN LDO3_PULLDOWN LDO4_PULLDOWN LDO5_PULLDOWN BUCK_PULLDOWN 1 – Pull down enabled 0 – Pull down disabled APU_TSD This bit defines either to reset registers or not before LP8720 automatically starts START UP sequence form Thermal Shutdown after cooling down if EN-pin is High. 1 – No change to registers – registers content stays the same as before Thermal Shutdown. 0 – Reset registers to default values before START UP from Thermal Shutdown. Register 0x0A (Read Only) TSD 1 – device is in Thermal Shutdown. 0 – device is NOT in Thermal Shutdown . TSD_EW 1 – device temperature is higher than Thermal Shutdown Early Warning threshold. 0 – device temperature is lower than Thermal Shutdown Early Warning threshold. Register 0x0B (Read Only) TSD_INT 1 – Interrupt that was caused by Thermal Shutdown 0 – No Interrupt that was caused by Thermal Shutdown TSD_EW 1 – Interrupt that was caused by Thermal Shutdown Early Warning 0 – No Interrupt that was caused by Thermal Shutdown Early Warning Note 1: all reads from this register are destructive (all bits are reset to 0 after reading). Note 2: read form this register releases IRQ_N-pin (if was pushed down). Register 0x0C TSD_MASK 1 – TSD interrupt is masked 0 – TSD interrupt is NOT masked TSD_EW_MASK 1 – TSD_EW interrupt is masked 0 – TSD_EW interrupt is NOT masked www.national.com 10 REFERENCE LP8720 has internal reference block creating all necessary references and biasing for all blocks. OSCILLATOR There is internal oscillator giving clock to the bucks and to logic control. VBATT=3.6V Parameter Typ Min Max Unit Oscillator frequency 2.0 1.9 2.1 MHz THERMAL SHUTDOWN The Thermal Shutdown (TSD) function monitors the chip temperature to protect the chip from temperature damage caused Parameter Typ Unit TSD *) 160 °C TSD_EW *) 125 °C TSD_EW Hysteresis *) 10 °C *) Guaranteed by design. 11 www.national.com LP8720 eg. by excessive power dissipation. The temperature monitoring function has two threshold values TSD and TSD_EW that result in protective actions. When TSD_EW +125ºC is exceeded, then IRQ_N is set to low and “1” is written to TSD_EW bit in both STATUS register and in INTERRUPT register. If the temperature exceeds TSD +160ºC, then PMU initiates Emergency Shutdown. The POWER UP operation after Thermal Shutdown can be initiated only after the chip has cooled down to the +115ºC threshold Support Functions LP8720 Absolute Maximum Ratings (Note 1, Note Operating Ratings 2) VBATT = VINB, VBATT VIN1, VIN2 All input-only pins Junction Temperature (TJ) Ambient Temperature (TA) Maximum Power Dissipation (TA = 70ºC), (Note 5) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VBATT = VINB, VBATT -0.3V to +6V VIN1, VIN2 -0.3V to VBATT+0.15V, max 6V All other pins -0.3V to VBATT+0.3V, max 6V Junction Temperature (TJ-MAX) 150ºC Storage Temperature -40 to 150ºC Maximum Continuous Power Dissipation PD-MAX (Note 3) 1.75 W ESD (Note 4) 2 kV HBM 200V MM (Note 1, Note 2) Thermal Properties 2.7 to 4.5V 2.5V to VBATT 0V to VBATT -40 to 125ºC -40 to 85ºC 1.2 W (Note 9) Junction-to-Ambient Thermal Resistance (θJA) (Jedec Standard Thermal PCB) Micro SMD 20 45°C/W Current Consumption Unless otherwise noted, VVBATT=VVINB =VVIN1=VVIN2=3.6V, GND=GNDB=0V, CVBATT=CVIN1=CVIN2=2.2 µF, CVINB=10 µF. Typical values and limits appearing in normal type apply for TJ=25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ= -40 to +125°C. (Note 6) Symbol Parameter Conditions Typ IQ(STANDBY) Battery Standby Current VBATT = 3.6V IQ(SLEEP) Battery Current in SLEEP Mode @ 0 load BUCK and all LDO’s enabled IQ(SLEEP) Battery Current in SLEEP Mode @ 0 load LDO1, LDO2, LDO3 and LDO4 enabled IQ(SLEEP) Battery Current in SLEEP Mode @ 0 load LDO3 enabled IQ(SLEEP) Battery Current in SLEEP Mode @ 0 load LDO1 and BUCK enabled IQ Battery Current @ 0 load BUCK and all LDO’s enabled 270 IQ Battery Current @ 0 load LDO1, LDO2, LDO3 and LDO4 enabled 230 IQ Battery Current @ 0 load LDO3 enabled 120 IQ Battery Current @ 0 load LDO1 and BUCK enabled 120 Limit Min Max Units 0.7 5 µA 190 270 µA 170 µA 100 150 100 µA µA 400 µA µA 200 µA µA Power on Reset Unless otherwise noted, VVBATT=VVINB =VVIN1=VVIN2=3.6V, GND=GNDB=0V, CVBATT=CVIN1=CVIN2=2.2 µF, CVINB=10 µF. Typical values and limits appearing in normal type apply for TJ=25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ= -40 to +125°C. (Note 6) Symbol Parameter Conditions Typ VPOR_HI POR higher threshold VVBATT rising 2.2 VPOR_LO POR lower threshold VVBATT falling (Note 7) 1.4 www.national.com 12 Limit Min Max 2.0 2.4 Units V V Unless otherwise noted, VVBATT=VVINB =VVIN1=VVIN2=3.6V, GND=GNDB=0V, CVBATT=CVIN1=CVIN2=2.2µF, CVINB=10µF. Typical values and limits appearing in normal type apply for TJ=25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ= -40 to +125°C. (Note 6) Symbol Parameter Conditions Typ Limit Min Max Units Logic and Control Inputs VIL Input Low Level EN, SCL, SDA, DVS VIH Input High Level EN, SCL, SDA, DVS 1.2 IIL Input Current All logic inputs RPD Pull Down Resistance From EN to GND 550 0.4 V -5 +5 µA 300 900 kΩ V Logic and Control Outputs VOL Output Low Level IRQ_N, SDA, IOUT=2mA VOH Output High Level IRQ_N, SDA are Open drain outputs. 13 0.4 NA V µA www.national.com LP8720 Logic and Control LP8720 Buck Converter Unless otherwise noted, VVBATT=VVINB =VVIN1=VVIN2=3.6V, GND=GNDB=0V, CVBATT=CVIN1=CVIN2=2.2 µF, CVINB=10 µF. Typical values and limits appearing in normal type apply for TJ=25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ= -40 to +125°C. (Note 6, Note 10) Symbol Parameter Conditions Typ 3.0V ≤ VIN ≤ 4.5V external resistor divider Limit Units Min Max 0.5 0.485 0.515 V 1.164 1.236 V VFB Feedback Voltage VBUCK Output Voltage, PWM Mode 3.0V ≤ VIN ≤ 4.5V 1.2 VVOUT,PFM Output Voltage regulation in (Note 7) PFM mode relative to regulation in PWM mode 1.5 % VOUT Line Regulation 3.0V ≤ VIN ≤ 4.5V IOUT = 10 mA 0.14 %/V VOUT Load Regulation 100mA ≤ IOUT ≤ 300mA 0.09 %/mA ILIM_PWM Switch Peak Current Limit PWM Mode @ 400 mA RDSON(P) P channel FET on resistance RDSON(N) N channel FET on resistance fOSC Internal Oscillator Frequency Efficiency TSTUP 900 3.0V ≤ VIN ≤ 4.5V Start Up Time VIN = 3.6V, ID = 100mA PWM Mode 310 500 mΩ 160 300 mΩ 2.1 2.3 MHz 2 IOUT = 5mA, PFM-mode VOUT = 1.2V (Note 7) 88 IOUT = 200mA, PWM-mode VOUT = 1.2V (Note 7) 90 IOUT = 0, VOUT = 1.2V (Note 7) 140 1.9 1.7 % µs Buck Output Voltage Programming in Register 0x06 and 0x07 www.national.com BUCK1_Vx VOUT BUCK1_Vx VOUT 5h’00 External resistor divider 5h’10 1.55 5h’01 0.80 5h’11 1.60 5h’02 0.85 5h’12 1.65 5h’03 0.90 5h’13 1.70 5h’04 0.95 5h’14 1.75 5h’05 1.00 5h’15 1.80 5h’06 1.05 5h’16 1.85 5h’07 1.10 5h’17 1.90 5h’08 1.15 5h’18 1.95 5h’09 1.20 5h’19 2.00 5h’0A 1.25 5h’1A 2.05 5h’0B 1.30 5h’1B 2.10 5h’0C 1.35 5h’1C 2.15 5h’0D 1.40 5h’1D 2.20 5h’0E 1.45 5h’1E 2.25 5h’0F 1.50 5h’1F 2.30 14 mA 500 LP8720 Output Voltage Selection Using External Resistor Divider The formula for output voltage selection is Buck1 output voltage can be programmed via the selection of the external feedback resistor network. VOUT – output voltage VFB – feedback voltage (0.5V) For any out voltage greater than or equal to 0.8V a transfer function zero should be added by the addition of a capacitor C1. The formula for calculation of C1 is: 30067508 VOUT will be adjusted to make the voltage at FB equal to 0.5V. The resistor from FB to ground RFB2 should be around 200 kΩ to keep the current drawn through the resistor network to a minimum but large enough that it is not susceptible to noise. With RFB2=200 kΩ and VFB at 0.5V, the current through the resistor feedback network will be 2.5 µA. For recommended component values see the table below. VOUT [V] RFB1 [kΩ] RFB2 [kΩ] C1 [pF] L [µH] COUT [µF] 15 1.0 200 200 18 2.2 10 1.2 280 200 12 2.2 10 1.4 360 200 10 2.2 10 1.5 360 180 10 2.2 10 1.6 440 200 8.2 2.2 10 1.85 540 200 6.8 2.2 10 www.national.com LP8720 LDO’s All LDO’s can be programmed through serial interface for 32 different output voltage value, which are summarized in the in the “LDO Output Voltage Programming” tables below. At the PMU power on, LDO’s start up according to the selected startup sequence and the default voltages after start-up sequence depend on startup setup. See section Power-On and Power-Off Sequences for details. For stability all LDO’s have to have connected to output an external capacitor COUT with recommended value of 1 µF. It is important to select the type of capacitor which capacitance will in no case (voltage, temperature, etc) be outside of limits specified in the LDO electrical characteristics. There are all together 5 LDO’s in LP8720 grouped as A-type LDO’s (LDO 2,3) D-type LDO’s (LDO 1,5) LO-type LDO (LDO4) The A-type LDO’s are optimized for supplying of analog loads and have ultra low noise (15 µVRMS) and excellent PSRR (70dB) performance. The D-type LDO’s are optimized for good dynamic performance to supply different fast changing (digital) loads. The LO-type LDO is optimized for low output voltage and for good dynamic performance to supply different fast changing (digital) loads. LDO4 Output Voltage Programming LDO1, 2, 3 and 5 Output Voltage Programming Data Code LDOx_V LDOx [V] Data Code LDOx_V LDOx [V] 5h’00 1.20 5h’10 2.10 5h’01 1.25 5h’11 2.20 5h’02 1.30 5h’12 2.30 5h’03 1.35 5h’13 2.40 5h’04 1.40 5h’14 2.50 5h’05 1.45 5h’15 2.60 5h’06 1.50 5h’16 2.65 5h’07 1.55 5h’17 2.70 5h’08 1.60 5h’18 2.75 5h’09 1.65 5h’19 2.80 5h’0A 1.70 5h’1A 2.85 5h’0B 1.75 5h’1B 2.90 5h’0C 1.80 5h’1C 2.95 5h’0D 1.85 5h’1D 3.00 5h’0E 1.90 5h’1E 3.10 5h’0F 2.00 5h’1F 3.30 www.national.com 16 Data Code LDO4_V LDO4 [V] Data Code LDO4_V LDO4 [V] 5h’00 0.80 5h’10 1.75 5h’01 0.85 5h’11 1.80 5h’02 0.90 5h’12 1.85 5h’03 1.00 5h’13 1.90 5h’04 1.10 5h’14 2.00 5h’05 1.20 5h’15 2.10 5h’06 1.25 5h’16 2.20 5h’07 1.30 5h’17 2.30 5h’08 1.35 5h’18 2.40 5h’09 1.40 5h’19 2.50 5h’0A 1.45 5h’1A 2.60 5h’0B 1.50 5h’1B 2.65 5h’0C 1.55 5h’1C 2.70 5h’0D 1.60 5h’1D 2.75 5h’0E 1.65 5h’1E 2.80 5h’0F 1.70 5h’1F 2.85 Unless otherwise noted, VVBATT=VVINB =VVIN1=VVIN2=3.6V, GND=GNDB=0V, CVBATT=CVIN1=CVIN2=2.2 µF, CVINB=10 µF. Typical values and limits appearing in normal type apply for TJ=25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ= -40 to +125°C. (Note 6) Symbol VOUT Parameter Output Voltage Accuracy Conditions IOUT = 1mA, VOUT = 2.85V LDO# Typ 2,3 Limit Units Min Max -2 +2 % -3 +3 % ISC Output Current Limit VOUT = 0V 2,3 600 VDO Dropout Voltage IOUT = IMAX (Note 8) 2,3 200 ΔVOUT Line Regulation VOUT + 0.5V ≤ VIN ≤ 4.5V IOUT = IMAX 2,3 1 mV mA 400 mV Load Regulation 1mA ≤ IOUT ≤ IMAX 2,3 5 mV eN Output Noise Voltage 10Hz ≤ f ≤ 100kHz COUT = 1µF (Note 7) 2,3 15 µVRMS PSRR Power Supply Ripple Rejection Ratio f=10kHz, COUT = 1µF IOUT = 20mA (Note 7) 2,3 70 dB tSTART UP Start-Up Time from Shutdown COUT = 1µF, IOUT = IMAX (Note 7) 2,3 35 µs VTransient Start-Up Transient Overshoot COUT = 1µF, IOUT = IMAX (Note 7) 2,3 COUT External output capacitance for stability 2,3 1.0 0.5 30 mV 20 µF D-Type and LO-Type LDO Electrical Characteristics Unless otherwise noted, VVBATT=VVINB =VVIN1=VVIN2=3.6V, GND=GNDB=0V, CVBATT=CVIN1=CVIN2=2.2 µF, CVINB=10 µF. Typical values and limits appearing in normal type apply for TJ=25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ= -40 to +125°C. (Note 6) Symbol VOUT Parameter Output Voltage Accuracy Conditions IOUT = 1mA, VOUT = 2.85V IOUT = 1mA, VOUT = 1.20V IOUT = 1mA, VOUT = 2.60V LDO# Typ 1,5 4 4 Limit Units Min Max -2 +2 % -3 +3 % -2 +2 % -3 +3 % -3 +3 % -4 +4 % ISC Output Current Limit VOUT = 0V 1,4,5 600 VDO Dropout Voltage IOUT = IMAX (Note 8) 1,4,5 190 ΔVOUT Line Regulation VOUT + 0.5V ≤ VIN ≤ 4.5V IOUT = IMAX 1,4,5 2 mV Load Regulation 1mA ≤ IOUT ≤ IMAX 1,4,5 5 mV eN Output Noise Voltage 10Hz ≤ f ≤ 100kHz COUT = 1µF (Note 7) 1,4,5 100 µVRMS PSRR Power Supply Ripple Rejection Ratio f=10kHz, COUT = 1µF IOUT = 20mA (Note 7) 1,4,5 55 dB tSTART UP Start-Up Time from Shutdown COUT = 1µF, IOUT = IMAX (Note 7) 1,4,5 35 µs VTransient Start-Up Transient Overshoot COUT = 1µF, IOUT = IMAX (Note 7) 1,4,5 COUT External output capacitance for stability 1,4,5 17 1.0 mA 400 0.5 mV 30 mV 20 µF www.national.com LP8720 A-Type LDO Electrical Characteristics LP8720 Serial Interface Unless otherwise noted, VVBATT=VVINB =VVIN1=VVIN2=3.6V, GND=GNDB=0V, CVBATT=CVIN1=CVIN2=2.2 µF, CVINB=10 µF. Typical values and limits appearing in normal type apply for TJ=25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ= -40 to +125°C. (Note 6, Note 7) Symbol Parameter Conditions Typ Limit Min Max Units fCLK Clock Frequency tBF Bus-Free Time between START and STOP 1.3 µs tHOLD Hold Time Repeated START Condition 0.6 µs tCLK-LP CLK Low Period 1.3 µs tCLK-HP CLK High Period 0.6 µs tSU Set-Up Time Repeated START Condition 0.6 µs tDATA-HOLD Data Hold Time 50 ns tDATA-SU Data Set-Up Time 100 ns tSU Set-Up Time for STOP Condition 0.6 µs tTRANS Maximum Pulse Width of Spikes that Must Be Suppressed by the Input Filter of Both DATA & CLK Signals 400 50 kHz ns Notes to Electrical Characteristics Tables Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the Electrical Characteristics tables. Note 2: All voltages are with respect to the potential at the GND pin. Note 3: The Absolute Maximum power dissipation depends on the ambient temperature and can be calculated using the formula P = (TJ – TA)/θJA, (eq. 1) where TJ is the junction temperature, TA is the ambient temperature, and θJA is the junction-to-ambient thermal resistance. The 1.75W rating appearing under Absolute Maximum Ratings results from substituting the Absolute Maximum junction temperature, 150ºC for TJ, 70ºC for TA, and 45°C/W for θJA. More power can be dissipated safely at ambient temperatures below 70°C. Less power can be dissipated safely at ambient temperatures above 70°C. The Absolute Maximum power dissipation can be increased by 22mW for each degree below 70°C, and it must be de-rated by 22 mW for each degree above 70ºC. Note 4: The human-body model is 100 pF discharged through 1.5 kΩ. The machine model is a 200 pF capacitor discharged directly into each pin, MIL-STD-883 3015.7. Note 5: Like the Absolute Maximum power dissipation, the maximum power dissipation for operation depends on the ambient temperature. The 1.2W rating for Micro SMD 20 appearing under Operating Ratings results from substituting the maximum junction temperature for operation, 125°C, for TJ, 70°C for TA, and 45° C/W for θJA into (eg. 1) above. More power can be dissipated at ambient temperatures below 70°C. Less power can be dissipated at ambient temperatures above 70°C. The maximum power dissipation for operation can be increased by 22mW for each degree below 70°C, and it must be de-rated by 22 mW for each degree above 70°C. Note 6: All limits are guaranteed. All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot and cold limits are guaranteed by correlating the electrical characteristics to process and temperature variations and applying statistical process control. Note 7: Guaranteed by design. Note 8: Dropout voltage is the input-to-output voltage difference at which the output voltage is 100mV below its nominal value. This specification does not apply in cases it implies operation with an input voltage below the 2.5V minimum appearing under Operating Ratings. For example, this specification does not apply for devices having 1.5V outputs because the specification would imply operation with an input voltage at or about 1.5V. Note 9: Junction-to-ambient thermal resistance is highly application and board-layout dependent. In applications where high maximum power dissipation exists, special care must be paid to thermal dissipation issues in board design. Note 10: Guaranteed for output voltages no less than 1.0V www.national.com 18 INTERFACE BUS OVERVIEW The I2C compatible synchronous serial interface provides access to the programmable functions and registers on the device. This protocol uses a two-wire interface for bi-directional communications between the IC’s connected to the bus. The two interface lines are the Serial Data Line (SDA), and the Serial Clock Line (SCL). These lines should be connected to a positive supply, via a pull-up resistor of 1.5 kΩ, and remain HIGH even when the bus is idle. Every device on the bus is assigned a unique address and acts as either a Master or a Slave depending on whether it generates or receives the serial clock (SCL). START AND STOP The Master device on the bus always generates the Start and Stop Conditions (control codes). After a Start Condition is generated, the bus is considered busy and it retains this status until a certain time after a Stop Condition is generated. A high-to-low transition of the data line (SDA) while the clock (SCL) is high indicates a Start Condition. A low-to-high transition of the SDA line while the SCL is high indicates a Stop Condition. DATA TRANSACTIONS One data bit is transferred during each clock pulse. Data is sampled during the high state of the serial clock (SCL). Consequently, throughout the clock’s high period, the data should remain stable. Any changes on the SDA line during the high state of the SCL and in the middle of a transaction, aborts the current transaction. New data should be sent during the low SCL state. This protocol permits a single data line to transfer both command/control information and data using the synchronous serial clock. 30067510 FIGURE 2. Start and Stop Conditions In addition to the first Start Condition, a repeated Start Condition can be generated in the middle of a transaction. This allows another device to be accessed, or a register read cycle. ACKNOWLEDGE CYCLE The Acknowledge Cycle consists of two signals: the acknowledge clock pulse the master sends with each byte transferred, and the acknowledge signal sent by the receiving device. The master generates the acknowledge clock pulse on the ninth clock pulse of the byte transfer. The transmitter releases the SDA line (permits it to go high) to allow the receiver to send the acknowledge signal. The receiver must pull down the SDA line during the acknowledge clock pulse and ensure that SDA remains low during the high period of the clock pulse, thus signaling the correct reception of the last data byte and its readiness to receive the next byte. 30067527 FIGURE 1. Bit Transfer Each data transaction is composed of a Start Condition, a number of byte transfers (set by the software) and a Stop 30067528 FIGURE 3. Bus Acknowledge Cycle 19 www.national.com LP8720 Condition to terminate the transaction. Every byte written to the SDA bus must be 8 bits long and is transferred with the most significant bit first. After each byte, an Acknowledge signal must follow. The following sections provide further details of this process. I2C-Compatible Serial Bus Interface LP8720 CONTROL REGISTER WRITE CYCLE • Master device generates start condition. • Master device sends slave address (7 bits) and the data direction bit (r/w = '0'). • Slave device sends acknowledge signal if the slave address is correct. • Master sends control register address (8 bits). • Slave sends acknowledge signal. • Master sends data byte to be written to the addressed register. • Slave sends acknowledge signal. • If master will send further data bytes the control register address will be incremented by one after acknowledge signal. • Write cycle ends when the master creates stop condition. ”ACKNOWLEDGE AFTER EVERY BYTE” RULE The master generates an acknowledge clock pulse after each byte transfer. The receiver sends an acknowledge signal after every byte received. There is one exception to the “acknowledge after every byte” rule. When the master is the receiver, it must indicate to the transmitter an end of data by not-acknowledging (“negative acknowledge”) the last byte clocked out of the slave. This “negative acknowledge” still includes the acknowledge clock pulse (generated by the master), but the SDA line is not pulled down. ADDRESSING TRANSFER FORMATS Each device on the bus has a unique slave address. The LP8720 operates as a slave device. Slave address is selectable by IDSEL-pin. When IDSEL= VBATT then slave address is 7h’7F When IDSEL= floating (Hi-Z) then slave address is 7h’7C When IDSEL= GND then slave address is 7h’7D Before any data is transmitted, the master transmits the address of the slave being addressed. The slave device should send an acknowledge signal on the SDA line, once it recognizes its address. The slave address is the first seven bits after a Start Condition. The direction of the data transfer (R/W) depends on the bit sent after the slave address — the eighth bit. When the slave address is sent, each device in the system compares this slave address with its own. If there is a match, the device considers itself addressed and sends an acknowledge signal. Depending upon the state of the R/W bit (1:read, 0:write), the device acts as a transmitter or a receiver. CONTROL REGISTER READ CYCLE • Master device generates a start condition. • Master device sends slave address (7 bits) and the data direction bit (r/w = '0'). • Slave device sends acknowledge signal if the slave address is correct. • Master sends control register address (8 bits). • Slave sends acknowledge signal. • Master device generates repeated start condition. • Master sends the slave address (7 bits) and the data direction bit (r/w = “1”). • Slave sends acknowledge signal if the slave address is correct. • Slave sends data byte from addressed register. • If the master device sends acknowledge signal, the control register address will be incremented by one. Slave device sends data byte from addressed register. • Read cycle ends when the master does not generate acknowledge signal after data byte and generates stop condition. Address Mode Data Read <Start Condition> <Slave Address><r/w = ‘0’>[Ack] <Register Addr.>[Ack] <Repeated Start Condition> <Slave Address><r/w = ‘1’>[Ack] [Register Data]<Ack or NAck> … additional reads from subsequent register address possible <Stop Condition> Data Write <Start Condition> <Slave Address><r/w = ‘0’>[Ack] <Register Addr.>[Ack] <Register Data>[Ack] … additional writes to subsequent register address possible <Stop Condition> < > Data from master [ ] Data from slave www.national.com 20 LP8720 REGISTER READ AND WRITE DETAIL 30067529 FIGURE 4. Register Write Format 30067530 FIGURE 5. Register Read Format 21 www.national.com LP8720 Physical Dimensions inches (millimeters) unless otherwise noted Micro SMD 20 Package NS Package Number MKT-TLA2011A X1 = 1.970 mm ±0.030 mm X2 = 2.466 mm ±0.030 mm X3 = 0.600 mm ±0.075 mm www.national.com 22 LP8720 Notes 23 www.national.com LP8720 One Step-Down DC/DC and Five Linear Regulators with I2C Compatible Interface Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Design Support Amplifiers www.national.com/amplifiers WEBENCH® Tools www.national.com/webench Audio www.national.com/audio App Notes www.national.com/appnotes Clock and Timing www.national.com/timing Reference Designs www.national.com/refdesigns Data Converters www.national.com/adc Samples www.national.com/samples Interface www.national.com/interface Eval Boards www.national.com/evalboards LVDS www.national.com/lvds Packaging www.national.com/packaging Power Management www.national.com/power Green Compliance www.national.com/quality/green Switching Regulators www.national.com/switchers Distributors www.national.com/contacts LDOs www.national.com/ldo Quality and Reliability www.national.com/quality LED Lighting www.national.com/led Feedback/Support www.national.com/feedback Voltage References www.national.com/vref Design Made Easy www.national.com/easy www.national.com/powerwise Applications & Markets www.national.com/solutions Mil/Aero www.national.com/milaero PowerWise® Solutions Serial Digital Interface (SDI) www.national.com/sdi Temperature Sensors www.national.com/tempsensors SolarMagic™ www.national.com/solarmagic PLL/VCO www.national.com/wireless www.national.com/training PowerWise® Design University THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. 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