RTL8111H-CG from Realtek Semicon, in a QFN-32-EP(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	MDIP0	bidirectional	MDI pair 0 positive. In MDI mode, first pair for 1000BASE-T (BI_DA+); transmit pair for 10/100BASE-T(X). In MDI crossover mode acts as BI_DB+ (receive pair for 10/100BASE-T(X)).
2	MDIN0	bidirectional	MDI pair 0 negative. Complement of MDIP0 (BI_DA-/BI_DB-).
3	AVDD10	power_in	Analog 1.0V power supply.
4	MDIP1	bidirectional	MDI pair 1 positive. In MDI mode, second pair for 1000BASE-T (BI_DB+); receive pair for 10/100BASE-T(X). In MDI crossover mode acts as BI_DA+ (transmit pair for 10/100BASE-T(X)).
5	MDIN1	bidirectional	MDI pair 1 negative. Complement of MDIP1 (BI_DB-/BI_DA-).
6	MDIP2	bidirectional	MDI pair 2 positive. In MDI mode, third 1000BASE-T pair (BI_DC+). In MDI crossover mode acts as BI_DD+.
7	MDIN2	bidirectional	MDI pair 2 negative. Complement of MDIP2 (BI_DC-/BI_DD-).
8	AVDD10	power_in	Analog 1.0V power supply.
9	MDIP3	bidirectional	MDI pair 3 positive. In MDI mode, fourth 1000BASE-T pair (BI_DD+). In MDI crossover mode acts as BI_DC+.
10	MDIN3	bidirectional	MDI pair 3 negative. Complement of MDIP3 (BI_DD-/BI_DC-).
11	AVDD33	power_in	Analog 3.3V power supply.
12	CLKREQB	bidirectional	PCI Express Reference Clock Request (open drain, active low, 1.8V/3.3V compatible I/O; requires external pull-up). Used to request start of the PCIe reference clock and to initiate L1 exit under the L1.off mechanism.
13	HSIP	input	PCI Express Receive Differential Pair, positive (2.5GT/s, x1).
14	HSIN	input	PCI Express Receive Differential Pair, negative (2.5GT/s, x1).
15	REFCLK_P	input	PCI Express Differential Reference Clock, positive (100MHz ± 300ppm).
16	REFCLK_N	input	PCI Express Differential Reference Clock, negative (100MHz ± 300ppm).
17	HSOP	output	PCI Express Transmit Differential Pair, positive (2.5GT/s, x1).
18	HSON	output	PCI Express Transmit Differential Pair, negative (2.5GT/s, x1).
19	PERSTB	input	PCI Express Reset (active low, 1.8V/3.3V compatible input). When asserted at power-on, the device returns to a predefined reset state and is ready for initialization after de-assertion.
20	ISOLATEB	input	Isolate pin (active low, 1.8V/3.3V compatible input). Used to isolate the device from the PCI Express bus; while asserted, PCIe outputs (except LANWAKEB) are not driven and PCIe inputs are not sampled. Follows system state S0 high, S3/S4 low.
21	LANWAKEB	bidirectional	Power Management Event (open drain, active low, 1.8V/3.3V compatible I/O; requires external pull-up). Used to reactivate the PCI Express slot's main power rails and reference clocks.
22	DVDD10	power_in	Digital 1.0V power supply (core).
23	VDDREG	power_in	Digital 3.3V power supply for the internal Switching/LDO regulator.
24	REGOUT	power_out	Regulator 1.0V output. On RTL8111H this is the LDO regulator output; on RTL8111HS it is the switching regulator output.
25	LED2	output	Customizable LED output 2. Function selected via IO register offset 18h~19h (default per Fixed LED Mode). Logic high during power down.
26	LED1/GPO	bidirectional	Dual-function: LED1 output (default) or General Purpose Input/Output (1.8V/3.3V compatible input, 3.3V output only). Only one function may be selected at a time via register.
27	LED0	output	Customizable LED output 0. Function selected via IO register offset 18h~19h. Logic high during power down.
28	CKXTAL1	input	Crystal/clock input, 25MHz or 48MHz reference. Connect to one terminal of the crystal or drive with an external clock source.
29	CKXTAL2	bidirectional	Crystal/clock output (and input when using an external clock source). 25MHz or 48MHz reference.
30	AVDD10	power_in	Analog 1.0V power supply.
31	RSET	passive	Bias reference; connect an external precision resistor to ground to set internal bias current.
32	AVDD33	power_in	Analog 3.3V power supply.
33	GND	power_in	Ground (exposed pad on package bottom). Must be soldered to the board ground plane for electrical return and thermal dissipation.

Key specifications

Parameter	Value
Manufacturer	Realtek Semicon
Package	QFN-32-EP(4x4)
Category	Interface
Pins	33

Ordering variants

Same part, different packaging or reel option.

RTL8111H-CG
RTL8111HS-CG

CAD (KiCad official)

Symbol: RTL8111H-CG
Footprint: Package_DFN_QFN:QFN-32-1EP_4x4mm_P0.4mm_EP2.9x2.9mm
3D model: QFN-32-EP(4x4) (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Realtek Semicon datasheet (40 pp, sha256 283e5b9ee377fdd8, retrieved 2026-08-17, tier: lcsc)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF