A SOJ-32 package is a 32-lead small-outline J-lead package on 1.27 mm pitch, with 16 leads per long side folded back under the body. It ships in two widths that are not interchangeable: a 300-mil version with a 6.48 – 6.99 mm body, and a 400-mil version at 8.99 – 9.60 mm. Confirm which one you have before drawing anything.
Key takeaways
- Pitch is 1.27 mm and body length is 20.83 – 21.08 mm on both widths.
- JEDEC registers 32-pin SOJ under at least five different body widths, so the pin count alone tells you nothing about the footprint.
- A 400-mil SOJ-32 land pattern uses 1.70 × 0.60 mm pads with the two rows 9.40 mm apart, centre to centre.
- KiCad’s official library has no SOJ-32 footprint; the closest supported reference is its SOJ-36 400-mil part.
- Most SOJ-32 devices are byte-wide memory and share one 32-pin map, with pin 1 at top-left and numbering counterclockwise.
[IMAGE 1: dimensioned end view of a SOJ-32 with E, E1, E2 and A called out | alt: “SOJ-32 package dimensions showing body width, lead row spacing and overall lead span”]
SOJ-32 package dimensions, 300-mil and 400-mil
Alliance Semiconductor’s AS7C31024B datasheet (v1.2, 24 March 2004) specifies both widths for the same 32-pin die, so the two columns below differ only by package.
| Symbol | What it measures | 300-mil SOJ-32 | 400-mil SOJ-32 |
| e | Lead pitch | 1.27 mm BSC | 1.27 mm BSC |
| D | Body length | 20.83 – 21.08 mm | 20.83 – 21.08 mm |
| E | Plastic body width | 6.48 – 6.99 mm | 8.99 – 9.60 mm |
| E1 | Lead row dimension | 7.49 – 7.75 mm | 10.03 – 10.29 mm |
| E2 | Overall span across leads | 8.38 – 8.64 mm | 11.05 – 11.30 mm |
| A | Overall height | 3.25 – 3.68 mm | 3.35 – 3.71 mm |
| A1 | Standoff | 0.64 mm min | 0.64 mm min |
| A2 | Body thickness | 2.41 – 2.67 mm | 2.67 – 2.92 mm |
| b | Formed lead width | 0.41 – 0.51 mm | 0.38 – 0.51 mm |
| c | Lead thickness | 0.18 – 0.25 mm | 0.18 – 0.33 mm |
Table 1. SOJ-32 dimensions from Alliance Semiconductor AS7C31024B v1.2. The drawing is inch-controlled; millimetre values are converted.
The mil figure tracks E1, the lead row, not the plastic body. On the 300-mil part the body is 6.48 – 6.99 mm wide while the leads reach 8.38 – 8.64 mm overall. Build the footprint from E1 and E2.
Which JEDEC outlines cover 32 pins
Several reference pages state that SOJ parts above 28 pins are all 10.16 mm wide. The JEDEC index by device type, updated March 2026, does not support that.
| Registration | Family | Registered pin counts |
| MO-061 | 9.6 mm (.400″) body width SOJ | 28, 32, 36, 40, 44 |
| MO-077 | 7.62 mm (.300″) body width SOJ | 24, 25, 28, 32 |
| MO-119 | SOJ .300″ body width | 24, 28, 32, 36 |
| MO-120 | SOJ .350″ body width | 24, 28, 32, 36 |
| MO-121 | SOJ .330″ body width | 24, 28, 32, 36 |
| MO-124 | SOJ 12.70 mm body, 1.27 mm pitch | 32, 34, 36, 40, 70 |
| MO-199 | LSOJ | 28, 32, 36, 40, 42, 44, 50, 54, 70 |
| MO-200 | SOJ 2-high / 4-high (stacked) | 32, 44 |
Table 2. JEDEC Publication 95 outlines whose registered pin counts include 32.
Thirty-two leads appear under at least five distinct body widths, plus a stacked variant. “SOJ-32” is a pin count, not a footprint.
SOJ-32 footprint and land pattern
KiCad’s official library ships no SOJ-32; the SOJ-32 footprint lived in the deprecated SMD_Packages library. The supported reference for the same 400-mil J-lead row is SOJ-36_10.16×23.49mm_P1.27mm, generated from an ISSI drawing. Its lead-row geometry transfers directly to 32 leads.
| Feature | Value | Basis |
| Pad count | 32, 16 per side | — |
| Pad size | 1.70 × 0.60 mm | KiCad SOJ-36 400-mil footprint |
| Pad pitch | 1.27 mm | KiCad SOJ-36 400-mil footprint |
| Row spacing, centre to centre | 9.40 mm | KiCad SOJ-36 400-mil footprint |
| Outer extent across rows | 11.10 mm | Derived: 9.40 + 1.70 |
| Inner gap between rows | 7.70 mm | Derived: 9.40 − 1.70 |
| First to last pad centre | 19.05 mm | Derived: 15 × 1.27 |
| Courtyard width | 11.60 mm | KiCad SOJ-36 400-mil footprint |
| Pad corner radius | 25 % of the short side | KiCad SOJ-36 400-mil footprint |
Table 3. A 400-mil SOJ-32 land pattern, built from KiCad’s SOJ-36 400-mil lead-row geometry with 16 pads per side.
Cross-check that against Table 1 before releasing it. The pad outer extent of 11.10 mm sits just inside the 11.05 – 11.30 mm lead span of the Alliance 400-mil part, normal for a J-lead: the pad covers the outside of the curl and there is no heel extension. For a 300-mil device, scale the row spacing to that part’s E1 and E2 instead.
[IMAGE 2: SOJ-32 land pattern with pad size, pitch and row spacing dimensioned | alt: “SOJ-32 package footprint with 1.70 by 0.60 mm pads on 9.40 mm rows”]
SOJ-32 pinout for byte-wide memory
Nearly every SOJ-32 device is a byte-wide SRAM or DRAM. The map below is the AS7C31024B, a 128K × 8 SRAM; its 300-mil and 400-mil SOJ options share it.
| Pin | Signal | Pin | Signal |
| 1 | NC | 32 | VCC |
| 2 | A16 | 31 | A15 |
| 3 | A14 | 30 | CE2 |
| 4 | A12 | 29 | WE |
| 5 | A7 | 28 | A13 |
| 6 | A6 | 27 | A8 |
| 7 | A5 | 26 | A9 |
| 8 | A4 | 25 | A11 |
| 9 | A3 | 24 | OE |
| 10 | A2 | 23 | A10 |
| 11 | A1 | 22 | CE1 |
| 12 | A0 | 21 | I/O7 |
| 13 | I/O0 | 20 | I/O6 |
| 14 | I/O1 | 19 | I/O5 |
| 15 | I/O2 | 18 | I/O4 |
| 16 | GND | 17 | I/O3 |
Table 4. SOJ-32 pin assignment for the AS7C31024B 128K × 8 SRAM, per datasheet v1.2.
[IMAGE 3: SOJ-32 top view with pin 1 marker and signal names | alt: “SOJ-32 package pinout for a 32-pin byte-wide memory”]
Sourcing a SOJ-32 today
Alliance Memory and ISSI both still list 32-pin SOJ SRAM. ISSI offers the IS61C1024AL in 300-mil SOJ, 400-mil SOJ, TSOP I and sTSOP I, with the width in the order-code suffix, so read the ordering table rather than a distributor’s “SOJ-32” label.
Stock is uneven. DigiKey listed the 32-SOJ AS7C1024B-15JCN at 103 units and USD 7.38 at the time of writing, while neighbouring SOJ order codes in the same family showed none. For prototyping without a board spin, SOJ-to-DIP socket adapters exist from suppliers such as Winslow.
SOJ-32 design mistakes
- Assuming 32 pins means 400 mil. JEDEC registers 32-lead SOJ at .300″, .330″, .350″, .400″ and 12.70 mm bodies.
- Reusing a SOJ-36 footprint file unedited. The lead row transfers; the pad count and courtyard length do not.
- Carrying a pinout across a package change without re-reading the drawing.
- Planning AOI-only inspection. Part of a J-lead joint sits under the body and needs X-ray for Class 3 work.
SOJ-32 package FAQ
What are SOJ-32 package dimensions?
For the 400-mil variant: body 20.83 – 21.08 mm long and 8.99 – 9.60 mm wide, lead row 10.03 – 10.29 mm, overall lead span 11.05 – 11.30 mm, height 3.35 – 3.71 mm, pitch 1.27 mm. The 300-mil variant shares the length and pitch but measures 6.48 – 6.99 mm across the body.
What is the SOJ-32 footprint?
For a 400-mil part, 32 pads of 1.70 × 0.60 mm on 1.27 mm pitch, 16 per side, with the rows 9.40 mm apart centre to centre. That gives an outer extent of 11.10 mm and a pad row 19.05 mm long from first to last centre. Verify against your device’s own E1 and E2.
Is SOJ-32 the same as SOP-32?
No. SOJ uses J-leads folded under the body; SOP and SOIC use gull-wing leads that extend outward. Both families run at 1.27 mm pitch on 32 leads, but the land patterns differ and the packages do not swap.
Are SOJ-32 parts still in production?
Yes, mainly asynchronous SRAM from Alliance Memory and ISSI. Availability varies sharply by order code, with some in stock and adjacent codes showing zero. Treat SOJ-32 as a legacy supply line: fine for repairs and existing boards, risky as a new design commitment.
Before you release the footprint
Pull the drawing for the exact order code and read E1 and E2. If E2 lands near 11.1 mm you have a 400-mil part and Table 3 applies directly. If it lands near 8.5 mm, scale the row spacing to the 300-mil dimensions. Either way, name the footprint after the body width, not after the pin count.
