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PGA460: without output on OUTA and OUTB pin when i try to trigger a burst

user4395374
Prodigy 10 points
Part Number: PGA460

we designed a board baseed on the reference design of PGA460. i got a problem when i want to trigger a busrt, nothing but a high level on the OUTA and OUTB pin.

how to debugger with this problem?

blow is the register initialized value, and i confirmed the register write was successful.

my trigger cmd sequence is 0x55 0x00 0x01 0xFE

pga460_write_reg(0x00,0x00);
pga460_write_reg(0x00,0x00);
pga460_write_reg(0x01,0x00);
pga460_write_reg(0x02,0x00);
pga460_write_reg(0x03,0x00);
mdelay(100);
pga460_write_reg(0x04,0x00);
pga460_write_reg(0x05,0x00);
pga460_write_reg(0x06,0x00);
mdelay(100);
pga460_write_reg(0x07,0x00);
pga460_write_reg(0x08,0x00);
pga460_write_reg(0x0a,0x00);
mdelay(100);
pga460_write_reg(0x0b,0x00);
pga460_write_reg(0x0c,0x00);
pga460_write_reg(0x0d,0x00);
pga460_write_reg(0x0e,0x00);
mdelay(100);
pga460_write_reg(0x0f,0x00);
pga460_write_reg(0x10,0x00);
pga460_write_reg(0x11,0x00);
pga460_write_reg(0x12,0x00);
pga460_write_reg(0x13,0x00);
mdelay(100);
pga460_write_reg(0x14,0xAA);
pga460_write_reg(0x15,0xAA);
pga460_write_reg(0x16,0xAA);
pga460_write_reg(0x17,0x82);
pga460_write_reg(0x18,0x08);
pga460_write_reg(0x19,0x20);
mdelay(100);
pga460_write_reg(0x1A,0x80);
pga460_write_reg(0x1B,0x60);
pga460_write_reg(0x1C,0x8F);
pga460_write_reg(0x1D,0xA0);
pga460_write_reg(0x1E,0x04);
pga460_write_reg(0x1F,0x10);
mdelay(100);
pga460_write_reg(0x20,0x55);
pga460_write_reg(0x21,0x55);
pga460_write_reg(0x22,0x19);
pga460_write_reg(0x23,0x33);
pga460_write_reg(0x24,0xee);
mdelay(100);
pga460_write_reg(0x25,0x7c);
pga460_write_reg(0x26,0x4f);
pga460_write_reg(0x27,0x00);
pga460_write_reg(0x28,0x00);
pga460_write_reg(0x29,0x09);
pga460_write_reg(0x2A,0x09);

  • 0
    TI__Mastermind 27950 points
    user4395374,
    There are usually two reasons why the PGA460-Q1 will not excite the transducer:

    1) The threshold CRC error (THR_CRC_ERR) bit is high. Always write to the threshold registers upon power-up before attempting to burst.

    From the datasheet: At power-up, all threshold registers (Px_THR_XX) and threshold CRC register (THR_CRC) are not initialized to the default value which causes a CRC error and sets THR_CRC_ERR bit to 1. This occurrence indicates to the MCU that the configuration is not loaded properly. Writing to threshold registers reruns CRC calculation and updates the error bit.

    2) The supply over voltage shutdown threshold (VPWR_OV_TH) is exceeded. The VPWR_OV_TH can be set to one of four levels: 12.3, 17.7, 22.8, or 28.3V. If the voltage at the VPWR pin exceed the VPWR_OV_TH value, the PGA460 will not allow excitation via OUTA/B. Try setting your supply voltage to 10V, or maximize the VPWR_OV_TH value. The value should be 28.3V by default.