Functional Blocks Description
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SPRUIF8 – June 2017
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Copyright © 2017, Texas Instruments Incorporated
AM438x ePOS EVM Hardware
3.15 Magnetic Stripe Reader
This EVM provides a 7-pin connector, part number 0533980771, to connect to the magnetic stripe reader.
The magnetic stripe reader is connected to the ADC analog inputs 0 to 7 of the AM438x processor.
4
Power Supplies
This section describes how the power supplies required for the design are generated.
4.1
Power Source
The AM438x ePOS EVM uses an external AC to +5 VDC (rated 2.5 A minimum) power adapter. The
switch near the power cable is used for powering on and off. The main power is on when the power switch
is positioned away from the power supply jack. The main power is off when the power switch is positioned
closest to the power supply jack.
4.2
Power Sequencing
The power sequencing requirements of the AM438X processor (see the AM438x data sheet) are
automatically handled by the TPS65218 PMIC.
4.3
Power-Management IC Power Supplies
The AM438x ePOS EVM uses the TPS65218 power-management IC from TI. The I2C0 on the AM438x is
used to control the SmartReflex™ port and control port on the TPS65218 device. For the AM438x
processor, the following power supplies from the TPS65218 device are used (see
Table 1
).
Table 1. AM438x Power Supplies From TPS65218
TPS65218 Power Supply
AM438x Power Rail
Voltage (V)
VDCDC1
VDD_CORE
1.1 V
VDCDC2
VDD_MPU
1.1 V
VDCDC3
VDD2, VDDCA, VDDQ of LPDDR2
1.2 V
VLS1
VDD_DDR
1.2 V
V1_8D
VDDS_CLKOUT, VDDS_OSC, VDDS_SRAM_CORE_BG,
VDDS_SRAM_MPU_BB VDDS_PLL_DDR, VDDS_PLL_MPU,
VDDA1P8V_USB0, VDDA1P8V_USB1, VPP, VDDA_MC_ADC, VDDA_TS_ADC,
VDDS_CTM, VDDS, VDDS_RTC, COM8, Tamper, and ADC input sections
1.8 V
V1_0BAT
VDD_TPM
1.0 V
V1_8BAT
VDDS_TPM
1.8 V
V3_3D_AM438X from
TPS63031
VDDSHV 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
3.3 V
V5_0D
HDMI circuitry, USB0 power
5.0 V
Table 2. Other Power Supplies
Power Supply
Power Rail
Voltage (V)
V1_8LPDDR2 from
TPS78101
VDD1 of LPDDR2
1.8 V
V3_3D
NAND memory, QPSI flash, Ethernet PHY, SDMMC0, board ID memory, ARM
JTAG, buffers of FTDI section, LCD buffer, touchscreen, camera module, HDMI
buffer, audio codec, RS-232 sections, COM8 sections, smart card sections,
tamper header, platform test section, GPIO header, and printer
3.3 V
V3_3FTDI
FT2232 section from TPS79333
3.3 V
VBAT
LCD POWER generation, camera module, VCOM_BAT generation for COM8
module, USB1 power generation, platform test section, LEDs, GPIO header,
buzzer, printer
xx V
V1_2D
HDMI section power
1.2 V