SPV1020

SPV1020 Interleaved DC-DC boost converter with built-in MPPT algorithm Features ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ PWM mode DC-DC boost converter Duty cycle controlled by MPPT algorithm with 0.2% accuracy Operating voltage range 6.5 - 40 V Overvoltage, overcurrent, overtemperature protection Interleaved 4-phase topology Built-in soft-start Up to 98% efficiency Power capability 320 W at 40 V output Automatic transition to burst mode for improved efficiency at low solar radiation SPI interface For a cost effective application solution and to minimize size, the SPV1020 embeds Power MOSFETs for active switches and synchronous rectifiers, minimizing the number of external devices. In addition, the 4-phase interleaved topology of the DC-DC converter obviates the need to use electrolytic capacitors, which may severely limit system lifetime. The SPV1020 operates at fixed frequency in PWM mode, where the duty cycle is controlled by the embedded logic running a Perturb&Observe MPPT algorithm. The switching frequency, internally generated and set by default at 100 kHz, is externally adjustable from 50 kHz to 200 kHz, while the duty cycle can range from 5% to 90% with a step of 0.2%. The safety of the application is guaranteed by stopping the drivers in the case of output overvoltage or overtemperature. Multiple SPV1020s can be used in a panel array with one SPV1020 per panel. Panels can be connected in series, in parallel, or series/parallel combinations. Table 1. Device summary Package PowerSSO-36 Packaging Tube PowerSSO-36 Applications ■ ■ Photovoltaic panels Battery charging with a CVCC controller Description The SPV1020 is a monolithic 4-phase interleaved DC-DC boost converter designed to maximize the power generated by photovoltaic panels independent of temperature and amount of solar radiation. Optimization of the power conversion is obtained with embedded logic which performs the MPPT (max. power point tracking) algorithm on the PV cells connected to the converter. One or more converters can be housed in the connection box of the PV panels, replacing the bypass diodes. As the maximum power point is locally computed, the efficiency at system level is higher than that of conventional topologies, where the MPP is computed in the main centralized inverter. Order codes SPV1020 January 2012 Doc ID 17588 Rev 3 1/19 www.st.com 19 Contents SPV1020 Contents 1 2 3 Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4 5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 Initialization and startup mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Input voltage sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Output voltage sensing and overvoltage protection (OVP) . . . . . . . . . . . . 10 Overcurrent protection (OCP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Overtemperature protection (OTP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Undervoltage lockout (UVLO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 MPPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 SPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 SPI timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6 7 8 Typical curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2/19 Doc ID 17588 Rev 3 SPV1020 Application circuit 1 Application circuit Figure 1. Application circuit Doc ID 17588 Rev 3 3/19 Pin connection SPV1020 2 Pin connection Figure 2. Pin connection (top view) 4/19 Doc ID 17588 Rev 3 SPV1020 Pin connection Table 2. Pin description Pin Name Type Supply Supply Ground Ground I I/O Description DC input power supply unit. Booster output voltage Power ground Signal ground reference. The exposed pad is connected to PGND. Booster inductor connection. External bootstrap capacitors must be connected between these pins and LXi Power supply for internal low voltage circuitry; an external capacitor must be connected to this pin referenced to SGND Sense pin of input voltage. To be biased with a resistor divider between VIN and SGND Sense pin of output voltage. To be biased with a resistor divider between VOUT and SGND Activates the SPI Dedicated ground for VIN_SNS Compensates the output voltage feedback loop. A series resistor and capacitor are connected between PZ_OUT and SGND. Data OUT for SPI interface Clock for SPI interface. Data IN for SPI interface. Pin for adjusting the switching frequency; to set the default value of 100 kHz, connect OSC_IN to VREG. Otherwise connect OSC_IN through a resistor to SGND. PowerSSO-36 34 7,8,17,18,19,20,29,30 12,13,24,25 1 22,23,26,27,15,14,11,1 0 9,16,21,28 VIN VOUT PGND SGND LX1…4 CB1…4 5 VREG I/O 35 3 31 36 2 6 33 32 4 VIN_SNS VOUT_SNS XCS VIN_SNS_M PZ_OUT SPI_DATA_OUT SPI_CLK SPI_DATA_IN OSC_IN I I I I I/O O I I I Doc ID 17588 Rev 3 5/19 Maximum ratings SPV1020 3 3.1 Maximum ratings Absolute maximum ratings Table 3. Symbol Absolute maximum ratings Parameter Power supply Power supply Power ground Signal ground Analog input Analog input Analog input/output Analog input/output Analog input Analog input Analog input Analog input/output Range [min., max.] [-0.3, 40] [-0.3, 40] 0 [-0.3, 0.3] [-0.3, VOUT + 0.3] [-0.3, VOUT + 0.3] [Lxi – 0.3, Lxi + 5] [-0.3, 6] [-0.3, 3.3 + 0.3] [-0.3, 3.3 + 0.3] [-0.3, 3.3 + 0.3] [-0.3, VIN + 0.3] [-0.3, 3.3 + 0.3] [-0.3, 3.3 + 0.3] [-0.3, 3.3 + 0.3] [-0.3, 0.3] Unit V V V V V V V V V V V V V V V V VIN VOUT PGND SGND VOUT_SNS LX1….4 CB1…4 VREG VIN_SNS XCS OSC_IN PZ_OUT SPI_DATA_OUT Analog output SPI_CLK SPI_DATA_IN VIN_SNS_M Digital input Digital input Dedicated ground Table 4. Symbol RthJA Tjop Tstg Thermal data Parameter Thermal resistance, junction to ambient Junction temperature operating range Storage temperature -50 Min. Typ. Max. Unit °C 125 24 °C/W 6/19 Doc ID 17588 Rev 3 SPV1020 Electrical characteristics 4 Electrical characteristics VIN = 36 V, TA = 25 °C and TJ