BL6552 from BL Shanghai Belling, in a QFN-36-EP(6x6). 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	INP	input	Neutral-line current channel positive differential input. Max differential voltage per pair ±0.7V.
2	VREF	bidirectional	Internal 1.2V reference voltage; can be used as reference input or output. Decouple externally.
3	VAN	input	Phase-A voltage channel negative differential input. Max differential voltage per pair ±0.7V.
4	VAP	input	Phase-A voltage channel positive differential input.
5	VBN	input	Phase-B voltage channel negative differential input. Max differential voltage per pair ±0.7V.
6	VBP	input	Phase-B voltage channel positive differential input.
7	VCN	input	Phase-C voltage channel negative differential input. Max differential voltage per pair ±0.7V.
8	VCP	input	Phase-C voltage channel positive differential input.
9	NRST	input	Active-low reset input.
10	AGND	power_in	Analog ground.
11	DGND	power_in	Digital ground.
12	CS	input	SPI chip-select input when SEL=1; when SEL=0 acts as UART baud-rate select input.
13	SDO	output	SPI MISO / UART TX output data pin (function selected by SEL).
14	SDI	input	SPI MOSI / UART RX input data pin (function selected by SEL).
15	SCLK	input	SPI clock input when SEL=1; when SEL=0 acts as UART baud-rate select input.
16	IRQ1	output	Interrupt-status logic output 1.
17	IRQ2	output	Interrupt-status logic output 2.
18	CLKOUT	output	Crystal oscillator output pin (connect to external 8MHz crystal).
19	CLKIN	input	Crystal oscillator input pin; external crystal frequency 8MHz.
20	VPP	power_in	Reserved power pin; may be left floating.
21	CF1	output	Calibration pulse output 1 (active-power energy pulse).
22	CF2	output	Calibration pulse output 2 (reactive-power energy pulse).
23	AT1	output	Configurable logic output 1 (programmable status indication).
24	AT2	output	Configurable logic output 2 (programmable status indication).
25	AT3	output	Configurable logic output 3 (programmable status indication).
26	DVDD18	power_out	Internal 1.8V digital LDO output; connect an external 0.1µF filter capacitor to GND.
27	SEL	input	Interface select input: 0 (default) selects UART, 1 selects SPI.
28	DVDD	power_in	Digital 3.3V supply input.
29	AVDD	power_in	Analog 3.3V supply input.
30	ICN	input	Phase-C current channel negative differential input. Max differential voltage per pair ±0.7V.
31	ICP	input	Phase-C current channel positive differential input.
32	IBN	input	Phase-B current channel negative differential input. Max differential voltage per pair ±0.7V.
33	IBP	input	Phase-B current channel positive differential input.
34	IAN	input	Phase-A current channel negative differential input. Max differential voltage per pair ±0.7V.
35	IAP	input	Phase-A current channel positive differential input.
36	INN	input	Neutral-line current channel negative differential input. Max differential voltage per pair ±0.7V.

Key specifications

Parameter	Value
Manufacturer	BL Shanghai Belling
Package	QFN-36-EP(6x6)
Category	PMIC
Pins	36

CAD (KiCad official)

Symbol: BL6552
Footprint: Package_DFN_QFN:QFN-36-1EP_6x6mm_P0.5mm_EP3.7x3.7mm
3D model: QFN-36-EP(6x6) (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`bl6552.step`	396 KB	You want the bare part, or you mark your own boards.
`bl6552-etched.step`	2.0 MB	You want the part with `BL6552` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 493 faces against 230 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

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

Datasheet: BL Shanghai Belling datasheet (80 pp, sha256 4b18cbf018c6a304, retrieved 2026-08-17, tier: lcsc)
Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
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