L220-C 125kHz USB-C RFID reader in black, standing upright, three-quarter view

L220-C USB-C 125kHz EM4100 RFID Reader for Android Phones

The L220-C is a plug-in 125kHz RFID reader for Android phones and tablets with a USB-C port and OTG. It reads EM4100, TK4100 and compatible ID cards and key fobs at 0–30 mm, which built-in phone NFC cannot do, and types the 10-digit card number into any app.

Frequency: 125 kHz
Cards / tags: EM4100, TK4100, SMC4001 and EM4100-compatible 125kHz ID cards and key fobs
Interface: USB Type-C plug (USB OTG)
Output: Keyboard emulation: card number typed at the cursor
Read range: 0–30 mm front and back, 0–10 mm from the side

Request a quote for L220-C Order a sample Datasheet (PDF)

✓ Sample units for evaluation
✓ Output format confirmed for your software
✓ Private label & OEM options
✓ Reply within 1 business day

Why integrators choose the L220-C

125kHz on a phone — reads EM4100, TK4100 and SMC4001 ID cards and key fobs that 13.56MHz phone NFC cannot detect.
Types the card number — the 10-digit decimal number appears at the cursor in any Android app, with nothing to install.
Same default as the desktop reader — 10-digit decimal, like our L110-U USB reader, so phone and PC stations can share one format.
Quick tap reads — 0–30 mm face-on, 0–10 mm from the side, 0.2 s read time.
No battery — draws 5 V, 100 mA from the phone; 35 × 35 × 7 mm and about 20 g.

Why an Android phone needs extra hardware for 125kHz cards

Phone NFC works at 13.56 MHz. EM4100 and TK4100 proximity cards work at 125 kHz, a different frequency with a different air interface, so a phone's built-in NFC cannot read them, whatever app is installed. The L220-C adds a 125kHz reader through the USB-C port. For the background, see NFC reader vs RFID reader.

This matters on sites that already issued EM4100 badges or key fobs for doors, lockers or attendance, and now want staff to check or register those cards on a phone or tablet instead of at a PC.

Where the L220-C fits

Patrols and door checks. A guard reads a badge and looks the number up in a web-based access-control or visitor system.
Mobile attendance. Supervisors at building sites, depots or event gates record card numbers into a form or spreadsheet on a tablet.
Card enrollment in the field. Installers register new fobs into cloud access-control software from a phone, without carrying a laptop and a desktop reader.

For fixed PC stations, the L110-U desktop reader outputs the same default format. For 13.56MHz MIFARE cards, use the H220-C, which shares this housing.

Output format and matching your card records

An EM4100 card stores a 5-byte (40-bit) ID. The L220-C's default output is a 10-digit decimal number built from the last 4 bytes of that ID. This is the 10-digit number most often printed on EM4100 cards and fobs, so staff can compare the screen with the card in hand.

Many cards also carry a second printed number such as 123,45678: a 3-digit facility code and a 5-digit card number, the Wiegand 26 style that some access-control systems store instead. If your software expects that or any other format, tell us which one and a custom output format is set before shipment. See EM4100 and TK4100 cards explained, and convert sample numbers with the card number converter before you order.

L220-C specifications

General
Model	L220-C
Frequency	125 kHz
Form factor	Plug-in reader with USB-C plug, for phones and tablets
Color	Black or white

Cards & reading
Standard	EM4100 (read-only ID)
Supported cards	EM4100, TK4100, SMC4001 and EM4100-compatible 125kHz ID cards and key fobs
Read/write	Read-only (card ID)
Read range	0–30 mm front and back, 0–10 mm from the side
Read time	0.2 s
Read interval	0.5 s

Interface & output
Interface	USB Type-C plug (USB OTG)
Output	Keyboard emulation: card number typed at the cursor
Default format	10-digit decimal (4 bytes)
Custom format	On request
Host systems	Android with USB OTG; Windows XP / 7 / 10 through an OTG adapter
App or SDK	None required on Android

Physical & environment
Power	5 V, 100 mA from the host
Indicator	2-color LED (blue: power, green: status)
Dimensions	35 × 35 × 7 mm (without plug)
Weight	Approx. 20 g
Package	71 × 71 × 19 mm, approx. 50 g packed
Operating temperature	-20 °C to +70 °C

Specifications of L220-C as supplied for the standard version. Read range depends on the card or tag, mounting surface and environment — we can test your own cards before you order.

Download the L220-C datasheet (PDF, A4)

Card, tag and system compatibility

Works with

✓EM4100, TK4100 and SMC4001 125kHz ID cards and key fobs
✓Other EM4100-compatible 125kHz read-only ID cards
✓Android phones and tablets with a USB-C port and USB OTG support
✓Windows XP / 7 / 10 PCs through an OTG adapter

Not designed for

✕Writing, encoding or copying cards (read-only reader)
✕13.56MHz MIFARE and NFC cards — use the H220-C
✕125kHz proximity formats that are not EM4100-compatible (not listed)
✕134.2kHz FDX-B animal tags — use the A220-C
✕iPhone and iPad (iOS not listed for this model)
✕Phones and tablets without USB OTG support

Card not listed? Send us the card type or a photo and we will confirm compatibility before you buy.

Integration in 4 steps

1
Plug the L220-C into the USB-C port of an Android phone or tablet with USB OTG. If the device has an OTG switch in Settings, turn it on. The blue LED shows power.
2
Put the cursor in the field that should receive the card number. Android may hide the on-screen keyboard while the reader is connected; turn it back on in the keyboard settings if staff also type by hand.
3
Hold the card or fob against the reader face, within 30 mm. The 10-digit card number is typed at the cursor.
4
Compare the typed number with the number printed on a few of your cards. If your software stores a different format, ask for a custom output format before the production order.

OEM / ODM options for L220-C

◆Output format other than the default 10-digit decimal, on request, to match your access-control or attendance software
◆Housing color: black or white
◆Logo and private-label packaging on request; feasibility and terms confirmed in your quotation

How OEM/ODM projects work →

Typical applications

L220-C FAQ

Can my Android phone read 125kHz cards without the L220-C?

Not with its built-in NFC. Phone NFC works at 13.56 MHz, so it cannot detect 125kHz EM4100 or TK4100 cards. The L220-C adds a 125kHz reader through the USB-C port.

Does the number match what is printed on my EM4100 cards?

Usually, yes. The default output is the 10-digit decimal number that is most often printed on EM4100 cards. If your system uses the shorter facility code and card number printed next to it (for example 123,45678), ask for that as a custom output format; send a sample card and the format is confirmed before shipment.

Can the L220-C write or copy 125kHz cards?

No. The L220-C is a read-only reader. It reads the card ID number and types it at the cursor.

How fast can staff read a queue of cards?

Each read takes about 0.2 s and the reader has a 0.5 s read interval, so it handles one card after another at a normal tapping pace.