SM72445MT

Manufacturer Part NumberSM72445MT
DescriptionProgrammable Maximum Power Point Tracking Controller With Adjustable PWM Frequency
ManufacturerTI1 [Texas Instruments]
SM72445MT datasheet
 


1
Page 1
2
Page 2
3
Page 3
4
Page 4
5
Page 5
6
Page 6
7
Page 7
8
Page 8
9
Page 9
10
Page 10
11
12
13
14
15
16
17
18
19
Page 1/19

Download datasheet (351Kb)Embed
Next
Programmable Maximum Power Point Tracking Controller
With Adjustable PWM Frequency
General Description
The SM72445 is a programmable MPPT controller capable of
controlling four PWM gate drive signals for a 4-switch buck-
boost converter. The SM72445 also features a proprietary
algorithm called Panel Mode (PM) which allows for the panel
to be connected directly to the output of the power optimizer
circuit when the input to output voltage ratio is close to 1. This
provides an opportunity to optimize the efficiency of the power
optimizer when the load is naturally matching the maximum
power point of the panel. Along with the SM72295 (Photo-
voltaic Full Bridge Driver), it creates a solution for an MPPT
configured DC-DC converter with efficiencies up to 99.5%
(when operating with dedicated PM switches). Integrated into
the chip is an 8-channel, 10 bit A/D converter used to sense
input and output voltages and currents, as well as IC config-
uration. Externally programmable values include maximum
output voltage and current as well as different settings for slew
rate, soft-start and Panel Mode.
Block Diagram
© 2012 Texas Instruments Incorporated
SM72445
Features
Renewable Energy Grade
110kHz,135kHz or 215kHz PWM operating frequency
Panel Mode pin for optional bypass switch control
Programmable maximum power point tracking
Photovoltaic solar panel voltage and current diagnostic
Single inductor four switch buck-boost converter control
I2C interface for communication
Output overvoltage protection
Over-current protection
Package
TSSOP-28
FIGURE 1. Block Diagram
301761 SNVS795
March 7, 2012
30176102
www.ti.com

SM72445MT Summary of contents

  • Page 1

    Programmable Maximum Power Point Tracking Controller With Adjustable PWM Frequency General Description The SM72445 is a programmable MPPT controller capable of controlling four PWM gate drive signals for a 4-switch buck- boost converter. The SM72445 also features a proprietary algorithm ...

  • Page 2

    www.ti.com 2 ...

  • Page 3

    ... Connection Diagram Ordering Information Order Number Description SM72445MTX TSSOP-28 SM72445MTE TSSOP-28 SM72445MT TSSOP-28 30176103 FIGURE 3. Top View TSSOP-28 NSC Package Drawing Supplied As 2500 Units in Tape and MTC28 Reel 250 Units in Tape and MTC28 Reel MTC28 48 Units in Rail 3 Package Top Marking SM72445 ...

  • Page 4

    Pin Descriptions Pin Name 1 RST Active low signal. External reset input signal to the digital circuit. 2 NC1 Reserved for test only. This pin should be grounded. Digital supply voltage. This pin should be connected supply, ...

  • Page 5

    Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and specifications. Analog Supply Voltage V A (VDDA - VSSA) Digital Supply Voltage V D (VDDD - VSSD) Voltage on Any ...

  • Page 6

    Symbol Parameter PWM OUTPUT CHARACTERISTICS (Continued) A2 Low Frequency Setting: f PWM switching frequency PWM t Dead time DEAD Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which ...

  • Page 7

    Operation Description OVERVIEW The SM72445 is a programmable MPPT controller capable of outputting four PWM gate drive signals for a 4 switch buck- boost converter with an independent Panel Mode. The typical application circuit is shown in Figure 2. The ...

  • Page 8

    STARTUP SM72445 has a soft start feature that will ramp its output volt- age for a time of 250ms if the bridge is configured to run at 215kHz and up to 500ms if the bridge is configured for 110kHz. If ...

  • Page 9

    A2 PWM Frequency Panel Mode Operation setting 1.56 V LOW Uses dedicated PM 0.94 V MED. Uses dedicated PM 0.31 V HIGH Uses dedicated PM The user can also select the output voltage slew rate, mini- mum current threshold and ...

  • Page 10

    FIGURE 7. Sample Application for Panel Mode Operation RESET PIN When the reset pin is pulled low, the chip will cease its normal operation and turn-off all of its PWM outputs including the output of PM_OUT pin. Below is an ...

  • Page 11

    FIGURE 9. Equivalent Input Circuit DIGITAL INPUTS and OUTPUTS The digital input signals have an operating range where V = VDDA – VSSA. They are not prone to latch and may be ...

  • Page 12

    Register Description Bits Field 55:40 RSVD 39:30 ADC6 29:20 ADC4 19:10 ADC2 9:0 ADC0 reg1 Register Description Bits Field 55:41 RSVD 40 mppt_ok 39:30 Vout 29:20 Iout 19:10 Vin 9:0 Iin reg3 Register Description Bits Field 55:47 RSVD 46 ...

  • Page 13

    Register Description Bits Field Reset Value 55:32 RSVD 31:24 Vout offset 23:16 Iout offset 15:8 Vin offset 7:0 Iin offset reg5 Register Description Bits Field Reset Value 55:40 RSVD 39:30 iin_hi_th 29:20 iin_lo_th 19:10 iout_hi_th 9:0 iout_lo_th The open ...

  • Page 14

    The data registers in the SM72445 are selected by the Com- mand Register. The Command Register is offset from base address 0xE0. Each data register in the SM72445 falls into one of two types of user accessibility: 1) Read only ...

  • Page 15

    Noise coupling into digital lines greater than 400 mVp-p (typ- ical hysteresis) and undershoot less than 500 mV below GND, may prevent successful I2C communication with SM72445. I2C no acknowledge is the most common symptom, causing unnecessary traffic on the ...

  • Page 16

    Physical Dimensions www.ti.com NS Package Drawing MTC28 16 30176150 ...

  • Page 17

    Notes 17 www.ti.com ...

  • Page 18

    Notes ...

  • Page 19

    Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the ...