BETAPIN 1 · Ground
GroundGND
Function
Supply and segment-current return.
How to connect
Connect to the common ground and the bypass capacitors.
Six-digit LED driver with key scanning
TM1637 Pinout
Explore TM1637 pins, signal names, electrical functions and connection guidance for each package.
Package view
20Physical pins
TM1637DIP-20
Manufacturer-referencedTitan Micro Electronics
Pin diagram
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TM1637DIP-20Top view
TM1637SOP-20Top view
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PIN 2 · Segments / key scan
Open-drain sink / scanSEG1 / KS1
Function
Sinks current from segment 1; also provides key-scan timing.
How to connect
Connect to the shared cathodes of segment A across the display.
Electrical note
A set display bit enables the corresponding sink during the selected grid slot.
PIN 3 · Segments / key scan
Open-drain sink / scanSEG2 / KS2
Function
Sinks current from segment 2; also provides key-scan timing.
How to connect
Connect to the shared cathodes of segment B across the display.
Electrical note
A set display bit enables the corresponding sink during the selected grid slot.
PIN 4 · Segments / key scan
Open-drain sink / scanSEG3 / KS3
Function
Sinks current from segment 3; also provides key-scan timing.
How to connect
Connect to the shared cathodes of segment C across the display.
Electrical note
A set display bit enables the corresponding sink during the selected grid slot.
PIN 5 · Segments / key scan
Open-drain sink / scanSEG4 / KS4
Function
Sinks current from segment 4; also provides key-scan timing.
How to connect
Connect to the shared cathodes of segment D across the display.
Electrical note
A set display bit enables the corresponding sink during the selected grid slot.
PIN 6 · Segments / key scan
Open-drain sink / scanSEG5 / KS5
Function
Sinks current from segment 5; also provides key-scan timing.
How to connect
Connect to the shared cathodes of segment E across the display.
Electrical note
A set display bit enables the corresponding sink during the selected grid slot.
PIN 7 · Segments / key scan
Open-drain sink / scanSEG6 / KS6
Function
Sinks current from segment 6; also provides key-scan timing.
How to connect
Connect to the shared cathodes of segment F across the display.
Electrical note
A set display bit enables the corresponding sink during the selected grid slot.
PIN 8 · Segments / key scan
Open-drain sink / scanSEG7 / KS7
Function
Sinks current from segment 7; also provides key-scan timing.
How to connect
Connect to the shared cathodes of segment G across the display.
Electrical note
A set display bit enables the corresponding sink during the selected grid slot.
PIN 9 · Segments / key scan
Open-drain sink / scanSEG8 / KS8
Function
Sinks current from segment 8; also provides key-scan timing.
How to connect
Connect to the shared cathodes of segment DP across the display.
Electrical note
A set display bit enables the corresponding sink during the selected grid slot.
PIN 10 · Common-anode digits
High-side sourceGRID6
Function
Drives the common anode of digit 6.
How to connect
Connect to the common anode of display digit 6.
Electrical note
Use common-anode LEDs; these outputs are not logic-level GPIO.
PIN 11 · Common-anode digits
High-side sourceGRID5
Function
Drives the common anode of digit 5.
How to connect
Connect to the common anode of display digit 5.
Electrical note
Use common-anode LEDs; these outputs are not logic-level GPIO.
PIN 12 · Common-anode digits
High-side sourceGRID4
Function
Drives the common anode of digit 4.
How to connect
Connect to the common anode of display digit 4.
Electrical note
Use common-anode LEDs; these outputs are not logic-level GPIO.
PIN 13 · Common-anode digits
High-side sourceGRID3
Function
Drives the common anode of digit 3.
How to connect
Connect to the common anode of display digit 3.
Electrical note
Use common-anode LEDs; these outputs are not logic-level GPIO.
PIN 14 · Common-anode digits
High-side sourceGRID2
Function
Drives the common anode of digit 2.
How to connect
Connect to the common anode of display digit 2.
Electrical note
Use common-anode LEDs; these outputs are not logic-level GPIO.
PIN 15 · Common-anode digits
High-side sourceGRID1
Function
Drives the common anode of digit 1.
How to connect
Connect to the common anode of display digit 1.
Electrical note
Use common-anode LEDs; these outputs are not logic-level GPIO.
PIN 16 · Supply
SupplyVDD
Function
Powers the logic and display drivers.
How to connect
The example uses a regulated 5 V rail with 100 nF and 100 µF bypass near the IC.
Electrical note
Electrical and timing characteristics are specified at 4.5–5.5 V; follow the purchased part revision.
PIN 17 · Two-wire controls
Bidirectional dataDIO
Function
Transfers command, display and key bytes; the IC pulls this line LOW for acknowledgement.
How to connect
Use a 10 kΩ pull-up to 5 V and an open-drain or releasable host pin.
Electrical note
Release the line for the ninth ACK clock and when reading keys; never contend with the IC output.
PIN 18 · Two-wire controls
Clock inputCLK
Function
Clocks data on rising edges.
How to connect
Use a 10 kΩ pull-up to 5 V; the example host clocks at 100 kHz.
Electrical note
This two-wire protocol is not I²C: no slave address, and bytes are sent least-significant bit first.
PIN 19 · Key inputs
Key inputK1
Function
First row input for the 8 × 2 key matrix.
How to connect
Optional keys connect to the SEG/KS scan lines as shown in the manufacturer circuit.
Electrical note
Internal nominal 10 kΩ pull-down; leave unused key inputs unconnected.
PIN 20 · Key inputs
Key inputK2
Function
Second row input for the 8 × 2 key matrix.
How to connect
Read with command 0x42; one key code is returned.
Electrical note
Combined key presses are not supported; idle key data is 0xFF.