AT89LS52-16AU from Microchip Tech, in a TQFP-44(10x10). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	P1.5	bidirectional	Port 1 bit 5 with internal pull-up; alternate function MOSI for In-System Programming.
2	P1.6	bidirectional	Port 1 bit 6 with internal pull-up; alternate function MISO for In-System Programming.
3	P1.7	bidirectional	Port 1 bit 7 with internal pull-up; alternate function SCK for In-System Programming.
4	RST	input	Reset input; a high for two machine cycles while the oscillator is running resets the device, and the pin drives high for 98 oscillator periods after Watchdog timeout.
5	P3.0	bidirectional	Port 3 bit 0 with internal pull-up; alternate function RXD (serial input port).
6	NC	unconnected	No connect.
7	P3.1	bidirectional	Port 3 bit 1 with internal pull-up; alternate function TXD (serial output port).
8	P3.2	bidirectional	Port 3 bit 2 with internal pull-up; alternate function INT0 (external interrupt 0).
9	P3.3	bidirectional	Port 3 bit 3 with internal pull-up; alternate function INT1 (external interrupt 1).
10	P3.4	bidirectional	Port 3 bit 4 with internal pull-up; alternate function T0 (timer 0 external input).
11	P3.5	bidirectional	Port 3 bit 5 with internal pull-up; alternate function T1 (timer 1 external input).
12	P3.6	bidirectional	Port 3 bit 6 with internal pull-up; alternate function WR (external data memory write strobe).
13	P3.7	bidirectional	Port 3 bit 7 with internal pull-up; alternate function RD (external data memory read strobe).
14	XTAL2	output	Oscillator amplifier output (crystal connection).
15	XTAL1	input	Oscillator amplifier and internal clock circuit input (crystal connection).
16	GND	power_in	Ground.
17	GND	power_in	Ground (second GND pin on the TQFP package).
18	P2.0	bidirectional	Port 2 bit 0 with internal pull-up; emits address line A8 for external memory.
19	P2.1	bidirectional	Port 2 bit 1 with internal pull-up; emits address line A9 for external memory.
20	P2.2	bidirectional	Port 2 bit 2 with internal pull-up; emits address line A10 for external memory.
21	P2.3	bidirectional	Port 2 bit 3 with internal pull-up; emits address line A11 for external memory.
22	P2.4	bidirectional	Port 2 bit 4 with internal pull-up; emits address line A12 for external memory.
23	P2.5	bidirectional	Port 2 bit 5 with internal pull-up; emits address line A13 for external memory.
24	P2.6	bidirectional	Port 2 bit 6 with internal pull-up; emits address line A14 for external memory.
25	P2.7	bidirectional	Port 2 bit 7 with internal pull-up; emits address line A15 for external memory.
26	PSEN	output	Program Store Enable, the read strobe to external program memory.
27	ALE/PROG	output	Address Latch Enable output pulse (1/6 oscillator frequency) latching the low address byte for external memory, and program pulse input (PROG) during Flash programming.
28	NC	unconnected	No connect.
29	EA/VPP	input	External Access enable / programming voltage input (VPP) for Flash programming.
30	P0.7	bidirectional	Port 0 bit 7, open-drain bidirectional I/O; multiplexed address/data AD7 for external memory.
31	P0.6	bidirectional	Port 0 bit 6, open-drain bidirectional I/O; multiplexed address/data AD6 for external memory.
32	P0.5	bidirectional	Port 0 bit 5, open-drain bidirectional I/O; multiplexed address/data AD5 for external memory.
33	P0.4	bidirectional	Port 0 bit 4, open-drain bidirectional I/O; multiplexed address/data AD4 for external memory.
34	P0.3	bidirectional	Port 0 bit 3, open-drain bidirectional I/O; multiplexed address/data AD3 for external memory.
35	P0.2	bidirectional	Port 0 bit 2, open-drain bidirectional I/O; multiplexed address/data AD2 for external memory.
36	P0.1	bidirectional	Port 0 bit 1, open-drain bidirectional I/O; multiplexed address/data AD1 for external memory.
37	P0.0	bidirectional	Port 0 bit 0, open-drain bidirectional I/O; multiplexed address/data AD0 for external memory.
38	VCC	power_in	Supply voltage; device operating range is 2.7 V to 4.0 V.
39	NC	unconnected	No connect.
40	P1.0	bidirectional	Port 1 bit 0 with internal pull-up; alternate function T2 (Timer/Counter 2 external count input), clock-out.
41	P1.1	bidirectional	Port 1 bit 1 with internal pull-up; alternate function T2EX (Timer/Counter 2 capture/reload trigger and direction control).
42	P1.2	bidirectional	Port 1 bit 2 with internal pull-up.
43	P1.3	bidirectional	Port 1 bit 3 with internal pull-up.
44	P1.4	bidirectional	Port 1 bit 4 with internal pull-up.

Key specifications

Parameter	Value
Manufacturer	Microchip Tech
Package	TQFP-44(10x10)
Category	Embedded Processors & Controllers
Pins	44

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
Input Low Voltage (Except EA)	VIL	-0.5		0.7	V		30
Input Low Voltage (EA)	VIL1	-0.5		0.2	V	0.2 VCC-0.3 V as printed	30
Input High Voltage (Except XTAL1, RST)	VIH	0.2			V	min 0.2 VCC+0.9; max VCC+0.5	30
Input High Voltage (XTAL1, RST)	VIH1	0.7			V	min 0.7 VCC; max VCC+0.5	30
Output Low Voltage (Ports 1,2,3)	VOL			0.45	V	IOL = 0.8 mA	30
Output Low Voltage (Port 0, ALE, PSEN)	VOL1			0.45	V	IOL = 1.6 mA	30
Output High Voltage (Ports 1,2,3, ALE, PSEN)	VOH	2.4			V	IOH = -60 µA, VCC = 5V ± 10%	30
Output High Voltage (Port 0 external bus)	VOH1	2.4			V	IOH = -800 µA, VCC = 5V ± 10%	30
Logical 0 Input Current (Ports 1,2,3)	IIL			-50	µA	VIN = 0.45V	30
Logical 1 to 0 Transition Current	ITL			-150	µA	VIN = 2V, VCC = 5V ± 10%	30
Input Leakage Current (Port 0, EA)	ILI	-10		10	µA	0.45 < VIN < VCC	30
Reset Pulldown Resistor	RRST	50		300	KΩ		30
Pin Capacitance	CIO			10	pF	Test Freq. = 1 MHz, TA = 25°C	30
Power Supply Current, Active Mode	ICC			25	mA	Active Mode, 12 MHz	30
Power Supply Current, Idle Mode	ICC			6.5	mA	Idle Mode, 12 MHz	30
Power Supply Current, Power-down Mode	ICC			30	µA	VCC = 4.0V	30
Operating Voltage Range	VCC	2.7		4	V		1
Operating Temperature (Industrial)	TA	-40		85	°C		35
Oscillator Frequency	1/tCLCL	0		16	MHz		31
Operating Temperature (absolute max)		-55		125	°C		29
Storage Temperature		-65		150	°C		29
Voltage on Any Pin with Respect to Ground		-1		7	V		29
Maximum Operating Voltage				6.6	V		29
DC Output Current				15	mA		29
ALE Pulse Width	tLHLL	85			ns	16 MHz oscillator	31
Address Valid to ALE Low	tAVLL	22			ns	16 MHz oscillator	31
Address Hold After ALE Low	tLLAX	32			ns	16 MHz oscillator	31
ALE Low to Valid Instruction In	tLLIV			150	ns	16 MHz oscillator	31
PSEN Pulse Width	tPLPH	142			ns	16 MHz oscillator	31
PSEN Low to Valid Instruction In	tPLIV			82	ns	16 MHz oscillator	31
RD Pulse Width	tRLRH	275			ns	16 MHz oscillator	31
WR Pulse Width	tWLWH	275			ns	16 MHz oscillator	31
RD Low to Valid Data In	tRLDV			147	ns	16 MHz oscillator	31
Serial Programming Oscillator Frequency	1/tCLCL	3		16	MHz	TA = -40°C to 85°C, VCC = 2.7V - 4.0V	29
SCK Low to MISO Valid	tSLIV	10	16	32	ns	TA = -40°C to 85°C, VCC = 2.7V - 4.0V	29
Chip Erase Instruction Cycle Time	tERASE			500	ms	TA = -40°C to 85°C, VCC = 2.7V - 4.0V	29

CAD (KiCad official)

Symbol: AT89LS52-16AU
Footprint: Package_QFP:TQFP-44_10x10mm_P0.8mm
3D model: TQFP-44(10x10) (KiCad packages3D, STEP)
3D model files: at89ls52-16au-etched.step / at89ls52-16au-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); at89ls52-16au.step / at89ls52-16au.glb are the bare package body.

Provenance

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

Datasheet: Microchip Tech datasheet (39 pp, sha256 e828a7b72fa7d152, retrieved 2026-10-31, tier: manufacturer)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-sonnet-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF

AT89LS52-16AU

Verified AT89LS52-16AU

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

README