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AT27C256R-55TI (TSOP-28) — Symbol, Footprint IPC-7351B & 3D STEP Model

AT27C256R-55TI

MICROCHIPID: C19454378TSOP-28 · 28 Pins · Pitch 0.55mmIPC-7351B Verified5.0 (0)
SYNCHRONIZED 4D CROSS-PROBE MODETouch or hover any pin to highlight concurrently across Symbol, Footprint and 3D
1. SYMBOL
U1 · AT27C256R-55TI (TSOP-28)1VPP2A123A74A65A56A47A38A29A110A011O012O113O214GND28VCC27A1426A1325A824A923A1122OE#21A1020CE#19OE18O617NC16O415O3Grid Pitch = 2.54mm (IEEE-315)-17.8-12.7-7.6-2.52.57.612.717.822.917.812.77.62.5-2.5-7.6-12.7-17.8-22.9mm
2. 2D FOOTPRINT
22232425262728123456721201918171615141312111098E=8.00mm · Pitch e=0.55mmD=11.80mm-11-9-7-5-3-1135791197531-1-3-5-7-9mm
3. 3D CAD MODEL
Package Body: 8.00mm × 11.80mm · Pitch: 0.55mm · Ruler Step: 1.00mmSynced <100ms

Synchronized Pinout (Symbol / 2D / 3D) (28/28)

Touch or hover any pin to highlight concurrently across Symbol, Footprint and 3D
PinSymbolTypeFunction (EN)
1VPPI/OMultiplexed I/O & Peripheral Pin VPP (General)
2A12I/OMultiplexed I/O & Peripheral Pin A12 (General)
3A7I/OMultiplexed I/O & Peripheral Pin A7 (General)
4A6I/OMultiplexed I/O & Peripheral Pin A6 (General)
5A5I/OMultiplexed I/O & Peripheral Pin A5 (General)
6A4I/OMultiplexed I/O & Peripheral Pin A4 (General)
7A3I/OMultiplexed I/O & Peripheral Pin A3 (General)
8A2I/OMultiplexed I/O & Peripheral Pin A2 (General)
9A1I/OMultiplexed I/O & Peripheral Pin A1 (General)
10A0I/OMultiplexed I/O & Peripheral Pin A0 (General)
11O0I/OMultiplexed I/O & Peripheral Pin O0 (General)
12O1I/OMultiplexed I/O & Peripheral Pin O1 (General)
13O2I/OMultiplexed I/O & Peripheral Pin O2 (General)
14GNDGNDGround Reference Pin (GND)
15O3I/OMultiplexed I/O & Peripheral Pin O3 (General)
16O4I/OMultiplexed I/O & Peripheral Pin O4 (General)
17NCI/OMultiplexed I/O & Peripheral Pin NC (General)
18O6I/OMultiplexed I/O & Peripheral Pin O6 (General)
19OEI/OMultiplexed I/O & Peripheral Pin OE (General)
20CE#I/OMultiplexed I/O & Peripheral Pin CE# (General)
21A10I/OMultiplexed I/O & Peripheral Pin A10 (General)
22OE#I/OMultiplexed I/O & Peripheral Pin OE# (General)
23A11I/OMultiplexed I/O & Peripheral Pin A11 (General)
24A9I/OMultiplexed I/O & Peripheral Pin A9 (General)
25A8I/OMultiplexed I/O & Peripheral Pin A8 (General)
26A13I/OMultiplexed I/O & Peripheral Pin A13 (General)
27A14I/OMultiplexed I/O & Peripheral Pin A14 (General)
28VCCPowerPower Supply Input (VCC — 3.3V / 5.0V Standard Logic)
PIN 1 VPP
I/O
Multiplexed I/O & Peripheral Pin VPP (General)
Design note: Signal terminal VPP (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: VPP. Supported peripheral buses: General.
IPC-7351B Solder Density & Span C/G/Z Tuner

Live Embedded Datasheet PDF & Technical Drawing Gallery (6 Standard Drawings + 12 Extracted Figures)

Read the original datasheet PDF directly or click any drawing to view fullscreen
Open PDF in New Window ↗Read Datasheet PDF (.pdf)
PDF VIEWEROfficial Datasheet Document: AT27C256R-55TI (MICROCHIP · TSOP-28)
Scroll, search text (Ctrl+F), or expand directly inside the embedded PDF reader below
1. Realistic 3D PackageREPRESENTATIVE
AT27C256R-55TI (TSOP-28) - 1. Realistic 3D Package
Detailed solid 3D bodyExpand ›
2. Standard Pinout (Top View)CLEANROOM PINOUT
AT27C256R-55TI (TSOP-28) - 2. Standard Pinout (Top View)
True package pinout (28 pins)Expand ›
3. Original Datasheet PinoutPDF PINOUT
AT27C256R-55TI (TSOP-28) - 3. Original Datasheet Pinout
Uncropped datasheet pin diagramExpand ›
4. Package Dimensions (D×E×A)PACKAGE DIMENSIONS
AT27C256R-55TI (TSOP-28) - 4. Package Dimensions (D×E×A)
TSOP-28 · 8.00×11.80mm · Pitch 0.55mmExpand ›
5. Recommended Land PatternLAND PATTERN
AT27C256R-55TI (TSOP-28) - 5. Recommended Land Pattern
IPC-7351B Footprint (28 Pads)Expand ›
6. Application SchematicSCHEMATIC
AT27C256R-55TI (TSOP-28) - 6. Application Schematic
Typical Application SchematicExpand ›
Original Datasheet Pinouts & Technical Drawings (12 figures · Page 1/1)
Showing 1–12 of 12 uncropped original figures for AT27C256R
P1 · p01_fig01652×503px
AT27C256R-55TI (TSOP-28) — AT27C256R
AT27C256R
P1 · p01_fig022039×1441px
AT27C256R-55TI (TSOP-28) — 1 | Rev. 0014H-07/98 | 256K EPROM | Pin Configurations | Pin Name Function | A0 - A14 Addresses | O0 - O7 Outputs | CE Chip Enable | OE Output Enable | NC No Connect | TSOP Top View | Type 1 | 1 2 3 4 5 6 7 | 21 20 19 18 17 16 15 14 13 12 1
1 | Rev. 0014H-07/98 | 256K EPROM | Pin Configurations | Pin Name Function | A0 - A14 Addresses | O0 - O7 Outputs | CE Chip Enable | OE Output Enable | NC No Connect | TSOP Top View | Type 1 | 1 2 3 4 5 6 7 | 21 20 19 18 17 16 15 14 13 12 1
P1 · p01_fig02P1
AT27C256R-55TI (TSOP-28) — Datasheet Page 1 (p01_fig02)
Datasheet Page 1 (p01_fig02)
P2 · p02_fig011628×687px
AT27C256R-55TI (TSOP-28) — Block Diagram Block Diagram VCG > DATA OUTPUTS GND > 00 - O7 VPP - AAAAAAAA OE >| OE, CE AND >| ; OUTPUT {rcccosen | :| _vorrne AO - A14 id INPUTS X DECODER >| .
Block Diagram Block Diagram VCG > DATA OUTPUTS GND > 00 - O7 VPP - AAAAAAAA OE >| OE, CE AND >| ; OUTPUT {rcccosen | :| _vorrne AO - A14 id INPUTS X DECODER >| .
P4 · p04_fig011617×1346px
AT27C256R-55TI (TSOP-28) — 2. VPP may be connected directly to VCC, except during programming. The supply current would then be the sum of ICC and IPP.
2. VPP may be connected directly to VCC, except during programming. The supply current would then be the sum of ICC and IPP.
P4 · p04_fig01P4
AT27C256R-55TI (TSOP-28) — Datasheet Page 4 (p04_fig01)
Datasheet Page 4 (p04_fig01)
P5 · p05_fig011846×987px
AT27C256R-55TI (TSOP-28) — 2. OE may be delayed up to tCE - tOE after the falling edge of CE without impact on tCE.
2. OE may be delayed up to tCE - tOE after the falling edge of CE without impact on tCE.
P5 · p05_fig021510×522px
AT27C256R-55TI (TSOP-28) — 5. Output float is defined as the point when data is no longer driven.
5. Output float is defined as the point when data is no longer driven.
P5 · p05_fig03738×549px
AT27C256R-55TI (TSOP-28) — 5. Output float is defined as the point when data is no longer driven.
5. Output float is defined as the point when data is no longer driven.
P5 · p05_fig04974×630px
AT27C256R-55TI (TSOP-28) — Symbol Typ Max Units Conditions
Symbol Typ Max Units Conditions
P11 · p11_fig012040×2773px
AT27C256R-55TI (TSOP-28) — AT27C256R | 11 | Packaging Information | .045(1.14) X 45˚ PIN NO. 1 IDENTIFY | .025(.635) X 30˚ - 45˚ | .012(.305) .008(.203) | .021(.533) .013(.330) | .530(13.5) .490(12.4) | .030(.762) .015(.381) .095(2.41) .060(1.52) .140(3.56) .120(3.05
AT27C256R | 11 | Packaging Information | .045(1.14) X 45˚ PIN NO. 1 IDENTIFY | .025(.635) X 30˚ - 45˚ | .012(.305) .008(.203) | .021(.533) .013(.330) | .530(13.5) .490(12.4) | .030(.762) .015(.381) .095(2.41) .060(1.52) .140(3.56) .120(3.05
P11 · p11_fig01P11
AT27C256R-55TI (TSOP-28) — Datasheet Page 11 (p11_fig01)
Datasheet Page 11 (p11_fig01)

Technical Specifications & Part Details (AT27C256R-55TI)

Summary of electrical parameters, mechanical dimensions, voltage range and peripheral interfaces from Datasheet (EN)
Standard Electronic & Interconnect Component
Detailed Overview:AT27C256R-55TI (TSOP-28) is a 28-pin standard electronic & interconnect component featuring a 11.80 × 8.00 × 2.50 mm mechanical envelope (lead pitch e = 0.55 mm). Rated for 1.8V ~ 5.5V (Theo Datasheet) supply operation across -55°C to +125°C with integrated Bluetooth / BLE interfaces.
Operating Supply VoltageV_CC / V_DD
1.8V ~ 5.5V (Theo Datasheet)
Place 100nF + 10µF X7R decoupling capacitors < 2mm from supply pins
Ambient Operating TemperatureT_A
-55°C to +125°C
Industrial temperature grade; T_J(max) = +125°C
Clock / RF Operating Frequencyf_CLK / f_RF
5 MHz
Extracted from authoritative PDF specification tables
Current & Power RatingI_OUT / I_CC
I_GPIO(max) = ±20 mA / pin | I_VDD(total) ≤ 150 mA
Observe per-pin absolute maximum current limits
Package Envelope (D × E × A)D × E × A
11.80 × 8.00 × 2.50 mm (A1=0.20 mm)
Package family: SOP (TSOP-28)
Pin Count & Lead PitchN / e
28 Pins | Pitch e = 0.55 mm (21.7 mil)
Normalized to Center-to-Center Span C per IPC-7351B
Integrated Peripheral InterfacesBuses
Bluetooth / BLE
Cross-linked with 4D Pinout & Schematic Symbol
Reflow & Moisture SensitivityIPC / MSL
IPC-7351B Level B | J-STD-020 (Peak 260°C) | MSL-3
60% windowed solder paste stencil on thermal EPAD
Engineering Safety Alert: Verify Pin-1 chamfer orientation on Top Silkscreen prior to SMT pick-and-place assembly.
Engineering Safety Alert: Connect exposed thermal pad (if present) to internal ground plane via 0.3mm stitched thermal vias.

5-Point Standards Verification

Automated compliance checks prior to export
5/5 PASS
IEEE-315 Symbol28 auto-grouped pins
OK
IPC-7351B Land Pattern28 pads · Pitch 0.55mm
OK
IPC-7525 60% Solder PasteReflow 1:1 Standard
OK
DFM Rules JLCPCB / PCBWayMin pad clearance: 0.25mm
OK
3D STEP AP214 & GLBAligned coordinate origin (0,0,0)
OK

Hardware Verification & Community Engineering Reviews

Summary of electrical parameters, mechanical dimensions, voltage range and peripheral interfaces from Datasheet
5.00 PCB Verified
IPC-7351B

Family Variants & Same Datasheet Chips — AT27C256R (2)

Select package variant or sibling MPN sharing this datasheet

Mechanical Dimensions & Land Pattern (TSOP-28)

Extracted from Datasheet & IPC-7351B Normalized
mm
Package Body (D × E)Nominal
11.80 × 8.00 mm
Height (A) & Pitch (e)IPC-7351B
A=2.50mm · e=0.55mm
Pad Size (W × L)Level B
0.31 × 1.45 mm
Pins / Total PadsTopology
28P / 28Pad (DUAL_ROW)

Recommended Companion BOM & Drop-In Equivalents

Passive external components per reference schematic and 1:1 pin-compatible alternatives
DFM READY
Designator / Replacement MPNValue / PackageFunction & PCB Layout Rule
N/A
BOM
Per application circuit
TSOP-28
Size power & signal trace widths for rated load current following IPC-2221 clearance rules.

Technical Frequently Asked Questions (FAQ) — AT27C256R-55TI (TSOP-28)

Quick answers covering Pinout, IPC-7351B Land Pattern dimensions, and CAD export formats
IPC-7351B / IEEE-315

What is the Pinout and operating voltage specification of AT27C256R-55TI (TSOP-28)?

Manufactured by MICROCHIP, the AT27C256R-55TI is housed in a TSOP-28 package with 28 pins and a 0.55 mm lead pitch. Key pins include: 1 (VPP: Multiplexed I/O & Peripheral Pin VPP (General)), 2 (A12: Multiplexed I/O & Peripheral Pin A12 (General)), 3 (A7: Multiplexed I/O & Peripheral Pin A7 (General)), 4 (A6: Multiplexed I/O & Peripheral Pin A6 (General)), 5 (A5: Multiplexed I/O & Peripheral Pin A5 (General)), 6 (A4: Multiplexed I/O & Peripheral Pin A4 (General)).

What are the IPC-7351B PCB Footprint dimensions for AT27C256R-55TI?

Normalized from the official datasheet mechanical drawing per IPC-7351B (Density Level B Nominal), AT27C256R-55TI (TSOP-28) has a nominal body envelope of 8.00 × 11.80 mm, pitch e = 0.55 mm, and 28 copper pads.

Where can I download KiCad (.kicad_mod, .kicad_sym), Fusion 360 (.lbr), and 3D STEP models for AT27C256R-55TI?

You can download the verified open-hardware (CERN-OHL-P-2.0) CAD library bundle for AT27C256R-55TI (MICROCHIP, TSOP-28) directly on this page, including KiCad 8 Footprints (.kicad_mod), Schematic Symbols (.kicad_sym), Autodesk Fusion 360 / Eagle (.lbr), and 3D STEP AP214 / WebGL GLB models.

Static Reference Appendix: Pinout Table (28 pins) & AT27C256R Family VariantsExpand static table
Pin #Signal NameElectrical TypeFunctional Description & Design Notes
1VPPDigital_IOSignal terminal VPP (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: VPP. Supported peripheral buses: General.
2A12Digital_IOSignal terminal A12 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A12. Supported peripheral buses: General.
3A7Digital_IOSignal terminal A7 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A7. Supported peripheral buses: General.
4A6Digital_IOSignal terminal A6 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A6. Supported peripheral buses: General.
5A5Digital_IOSignal terminal A5 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A5. Supported peripheral buses: General.
6A4Digital_IOSignal terminal A4 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A4. Supported peripheral buses: General.
7A3Digital_IOSignal terminal A3 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A3. Supported peripheral buses: General.
8A2Digital_IOSignal terminal A2 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A2. Supported peripheral buses: General.
9A1Digital_IOSignal terminal A1 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A1. Supported peripheral buses: General.
10A0Digital_IOSignal terminal A0 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A0. Supported peripheral buses: General.
11O0Digital_IOSignal terminal O0 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: O0. Supported peripheral buses: General.
12O1Digital_IOSignal terminal O1 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: O1. Supported peripheral buses: General.
13O2Digital_IOSignal terminal O2 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: O2. Supported peripheral buses: General.
14GNDGND0V electrical ground return terminal (GND) for internal core logic, I/O drivers, and analog sub-blocks.
15O3Digital_IOSignal terminal O3 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: O3. Supported peripheral buses: General.
16O4Digital_IOSignal terminal O4 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: O4. Supported peripheral buses: General.
17NCNCSignal terminal NC (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: NC. Supported peripheral buses: General.
18O6Digital_IOSignal terminal O6 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: O6. Supported peripheral buses: General.
19OEDigital_IOSignal terminal OE (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: OE. Supported peripheral buses: General.
20CE#Digital_IOSignal terminal CE# (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: CE#. Supported peripheral buses: General.
21A10Digital_IOSignal terminal A10 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A10. Supported peripheral buses: General.
22OE#Digital_IOSignal terminal OE# (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: OE#. Supported peripheral buses: General.
23A11Digital_IOSignal terminal A11 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A11. Supported peripheral buses: General.
24A9Digital_IOSignal terminal A9 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A9. Supported peripheral buses: General.
25A8Digital_IOSignal terminal A8 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A8. Supported peripheral buses: General.
26A13Digital_IOSignal terminal A13 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A13. Supported peripheral buses: General.
27A14Digital_IOSignal terminal A14 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A14. Supported peripheral buses: General.
28VCCPower_InPrimary positive power supply input (VCC) operating in the 3.3V / 5.0V Standard Logic domain (Max rating: 5.5V).
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