4.4.2 TMAG5111 Side
U13, C13, U12, C12, and R32 perform the same functions as the respective components from the TMAG5110
side but for the TMAG5111 signal path.
R31 and C10 create an RC filter which are combined with a dual Schmitt-Trigger buffer (U9, SN74LVC2G14)
and a single 2-input Exclusive-OR gate (U10, SN74LVC1G86) to create an edge detection circuit. The edge
detection circuit is used to convert the rising edge up/down counter (U13) to a dual edge up down counter to
count every clock transition from the TMAG5111 (U11).
4.5 LED Array Decoder Block
This block converts the BCD number of 0–9 to a position in an LED array that lights up in either green or blue
based on the direction of magnet rotation.
4.5.1 TMAG5110 Side
U4 is the CD74HC42, which is a BCD-to-decimal decoder. This device takes the BCD number and activates one
of 10 outputs accordingly (active low). C4 is a bypass capacitor that is placed near the IC to help mitigate power
supply noise and provide current quickly to the device when needed.
U5–U7 are each a TMUX1574, which are 2:1 (SPDT) 4-channel, powered-off protection switches that are used
to split each output from U4 into two outputs. The direction line from U2 is used as an input to the switches to
determine which of the two outputs should be active. C5–C7 are bypass capacitors that are placed near the ICs
to help mitigate power supply noise and provide current quickly to the devices when needed.
Each output pair from U5–U7 connects to an individual RGB LED (in D1–D10), with one output going into the
blue LED and the other output into the green LED. Because the switches U5–U7 are toggled from the direction
line, the LEDs will show green or blue based on the direction the magnet is rotating. The specific LED lit up will
be based on the BCD number 0–9 from the up/down counter (U3). R7–R27 are used as current-limiting resistors
for the LEDs.
4.5.2 TMAG5111 Side
U14, C4, U15–U17, C16–C17, D11–D20, R33–R52 perform the same functions as the respective components
from the TMAG5110 side but for the TMAG5111 signal path, except that the direction line comes directly from the
TMAG5111.
Circuitry
12
TMAG5110-5111EVM Evaluation Module
SLYU050B – JUNE 2020 – REVISED JULY 2021
Copyright © 2021 Texas Instruments Incorporated