MIL-STD-1553 Multiplex Data Bus Transformer

Pico Electronics offers two series of MIL-STD-1553 compliant transformers designed for aerospace and military applications. The 65000 series provides a surface mount alternative to traditional through-hole MIL-PRF-21038/27 data-bus transformers, featuring gull wing terminals for easier PCB assembly. Meanwhile, the LL-68500 series, available in both through-hole (TH) and surface mount (SM) versions, focuses on minimizing leakage inductance and DC resistance. Both series ensure reliable data transmission and electrical isolation, with the LL-68500 series specifically engineered for transparent signal processing and minimal distortion. These transformers exemplify Pico’s commitment to providing compact, high-performance solutions for MIL-STD-1553 interface requirements in critical aerospace and military systems.

For more information on our qualified military products, or QPL data-bus transformers, please visit our separate page for MIL-spec partsOpens a new window.

Part Number	Series	Mounting	Turns Ratio (±3%)	Primary Terminals	Secondary Terminals	DC Resistance Ω (max.)	Impedance Ω (Min.)	Typ. Leakage Inductance (μH)	Size (L x W x H) inches	Downloads
LL-68585-TH	LL-68500-TH	Through Hole	1.41:1 2:1	1-3	4-8 5-7	(1-3) 2.07 (4-8) 0.98	3000	(1-3) 4.5	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68585-SM	LL-68500-SM	Surface Mount	1.41:1 2:1	1-3	4-8 5-7	(1-3) 2.07 (4-8) 0.98	3000	(1-3) 4.5	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68580-TH	LL-68500-TH	Through Hole	2.12:1 1.5:1	4-8 5-7	1-3	(1-3) 0.81 (4-8) 2.82	3000	(4-8) 10.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68580-SM	LL-68500-SM	Surface Mount	2.12:1 1.5:1	4-8 5-7	1-3	(1-3) 0.81 (4-8) 2.82	3000	(4-8) 10.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68575-TH	LL-68500-TH	Through Hole	1:2.5 1:1.79	1-3	4-8 5-7	(1-3) 0.72 (4-8) 2.75	3000	(4-8) 4.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68575-SM	LL-68500-SM	Surface Mount	1:2.5 1:1.79	1-3	4-8 5-7	(1-3) 0.72 (4-8) 2.75	3000	(4-8) 4.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68570-TH	LL-68500-TH	Through Hole	1:1 1:0.707	1-3	4-8 5-7	(1-3) 2.07 (4-8) 1.32	3000	(4-8) 4.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68570-SM	LL-68500-SM	Surface Mount	1:1 1:0.707	1-3	4-8 5-7	(1-3) 2.07 (4-8) 1.32	3000	(4-8) 4.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68565-TH	LL-68500-TH	Through Hole	1:2.5	1-3	4-6	(1-3) 0.50 (4-6) 2.10	3000	(4-6) 5.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68565-SM	LL-68500-SM	Surface Mount	1:2.5	1-3	4-6	(1-3) 0.50 (4-6) 2.10	3000	(4-6) 5.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68560-TH	LL-68500-TH	Through Hole	1:1.79	1-3	4-6	(1-3) 0.71 (4-6) 2.05	3000	(4-6) 5.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68560-SM	LL-68500-SM	Surface Mount	1:1.79	1-3	4-6	(1-3) 0.71 (4-6) 2.05	3000	(4-6) 5.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68555-TH	LL-68500-TH	Through Hole	1:1.5	1-3	4-6	(1-3) 0.75 (4-6) 2.05	3000	(4-6) 5.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68555-SM	LL-68500-SM	Surface Mount	1:1.5	1-3	4-6	(1-3) 0.75 (4-6) 2.05	3000	(4-6) 5.2	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68550-TH	LL-68500-TH	Through Hole	1:2.5 1:1.79	1-3	4-8 5-7	(1-3) 0.87 (4-8) 2.52	4000	(4-8) 7.1	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68550-SM	LL-68500-SM	Surface Mount	1:2.5 1:1.79	1-3	4-8 5-7	(1-3) 0.87 (4-8) 2.52	4000	(4-8) 7.1	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68545-TH	LL-68500-TH	Through Hole	2.12:1 1.5:1	4-8 5-7	1-3	(1-3) 0.82 (4-8) 2.12	4000	(4-8) 8.0	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68545-SM	LL-68500-SM	Surface Mount	2.12:1 1.5:1	4-8 5-7	1-3	(1-3) 0.82 (4-8) 2.12	4000	(4-8) 8.0	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68540-TH	LL-68500-TH	Through Hole	1:2	1-3	4-6	(1-3) 0.52 (4-6) 2.05	3000	(4-6) 4.5	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68540-SM	LL-68500-SM	Surface Mount	1:2	1-3	4-6	(1-3) 0.52 (4-6) 2.05	3000	(4-6) 4.5	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68535-TH	LL-68500-TH	Through Hole	1:1.66	1-3	4-6	(1-3) 0.72 (4-6) 2.05	3000	(4-6) 2.73	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68535-SM	LL-68500-SM	Surface Mount	1:1.66	1-3	4-6	(1-3) 0.72 (4-6) 2.05	3000	(4-6) 2.73	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68530-TH	LL-68500-TH	Through Hole	1:1.41	1-3	4-6	(1-3) 0.80 (4-6) 2.05	3000	(4-6) 2.73	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68530-SM	LL-68500-SM	Surface Mount	1:1.41	1-3	4-6	(1-3) 0.80 (4-6) 2.05	3000	(4-6) 2.73	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68525-TH	LL-68500-TH	Through Hole	1:1	1-3	4-6	(1-3) 2.05 (4-6) 2.14	3000	(1-3) 2.73	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68525-SM	LL-68500-SM	Surface Mount	1:1	1-3	4-6	(1-3) 2.05 (4-6) 2.14	3000	(1-3) 2.73	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68520-TH	LL-68500-TH	Through Hole	1:1.41	1-3	4-6	(1-3) 0.82 (4-6) 1.95	3000	(4-6) 2.73	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68520-SM	LL-68500-SM	Surface Mount	1:1.41	1-3	4-6	(1-3) 0.82 (4-6) 1.95	3000	(4-6) 2.73	0.40 x 0.40 x 0.28	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68510-TH	LL-68500-TH	Through Hole	1.25:1 1.66:1	1-3	4-8 5-7	(1-3) 2.90 (4-8) 1.20	4000	(1-3) 4.7	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68510-SM	LL-68500-SM	Surface Mount	1.25:1 1.66:1	1-3	4-8 5-7	(1-3) 2.90 (4-8) 1.20	4000	(1-3) 4.7	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68505-TH	LL-68500-TH	Through Hole	1.4:1 2:1	1-3	4-8 5-7	(1-3) 2.90 (4-8) 1.08	7200	(1-3) 4.7	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68505-SM	LL-68500-SM	Surface Mount	1.4:1 2:1	1-3	4-8 5-7	(1-3) 2.90 (4-8) 1.08	7200	(1-3) 4.7	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
LL-68500-TH	LL-68500-TH	Through Hole	1:1 1:0.707	1-3	4-8 5-7	(1-3) 2.90 (4-8) 1.42	4000	(1-3) 4.7	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic 3D Step File
LL-68500-SM	LL-68500-SM	Surface Mount	1:1 1:0.707	1-3	4-8 5-7	(1-3) 2.90 (4-8) 1.42	4000	(1-3) 4.7	0.625 x 0.625 x 0.32	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68565	68500	Surface Mount	1:2.5	1-3	4-6	(1-3) 1.0 (4-6) 2.8	3000	–	0.40 x 0.40 x 0.25	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68560	68500	Surface Mount	1:1.79	1-3	4-6	(1-3) 0.9 (4-6) 2.5	3000	–	0.40 x 0.40 x 0.25	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68555	68500	Surface Mount	1:1.5	1-3	4-6	(1-3) 0.9 (4-6) 2.5	3000	–	0.40 x 0.40 x 0.25	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68550	68500	Surface Mount	1:2.5 1:1.79	1-3	4-8 5-7	(1-3) 1.0 (4-8) 3.5	4000	–	0.625 x 0.625 x 0.315	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68545	68500	Surface Mount	2.12:1 1.5:1	4-8 5-7	1-3	(1-3) 1.0 (4-8) 3.5	4000	–	0.625 x 0.625 x 0.315	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68540	68500	Surface Mount	1:2	1-3	4-6	(1-3) 1.3 (4-6) 2.6	3000	–	0.40 x 0.40 x 0.25	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68535	68500	Surface Mount	1:1.66	1-3	4-6	(1-3) 1.5 (4-6) 2.4	3000	–	0.40 x 0.40 x 0.25	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68530	68500	Surface Mount	1:1.41	1-3	4-6	(1-3) 2.2 (4-6) 2.7	3000	–	0.40 x 0.40 x 0.25	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68525	68500	Surface Mount	1:1	1-3	4-6	(1-3) 2.5 (4-6) 2.8	3000	–	0.40 x 0.40 x 0.25	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68520	68500	Surface Mount	1:1.41	1-3	4-6	(1-3) 2.2 (4-6) 2.7	3000	–	0.40 x 0.40 x 0.25	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68515	68500	Surface Mount	2.3:1 3.2:1	4-8 5-7	1-3	(1-3) 1.2 (4-8) 3.0	3000	–	0.625 x 0.625 x 0.315	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68510	68500	Surface Mount	1.25:1 1.66:1	1-3	4-8 5-7	(1-3) 3.2 (4-8) 3.0	4000	–	0.625 x 0.625 x 0.315	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68505	68500	Surface Mount	1.4:1 2:1	1-3	4-8 5-7	(1-3) 3.5 (4-8) 3.0	7200	–	0.625 x 0.625 x 0.315	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File
68500	68500	Surface Mount	1:1 1:0.707	1-3	4-8 5-7	(1-3) 3.0 (4-8) 3.0	4000	–	0.625 x 0.625 x 0.315	Datasheet Technical Drawing Electrical Schematic Land Pattern 3D Step File

Series Listing

A collection of six black electronic components labeled "PICO" with a green thumbtack, a silver paperclip, and a U.S. quarter for scale.

Series LL-68500 – Low Leakage Data Bus Transformers

3KΩ Min. & 2.7µH Leakage at 75KHz to 1MHz

A die, three black electronic components labeled "Pico 68000 Series," and a 2019 U.S. penny are arranged in a line on a white surface.

Series 68500 – Electrical SMD Equivalent to QPL MIL-PRF-21038/27

3KΩ Min. at 75KHz to 1MHz