---
title: "USB 1.1 vs USB 2.0"
subject: "Instrumentation II"
chapter: 3
key: "semester_5/instrumentation_ii:usb11-vs-usb20"
source: https://www.bctengineer.com/q/semester_5/instrumentation_ii/usb11-vs-usb20
site: BCT Engineering
---

# USB 1.1 vs USB 2.0

Instrumentation II · Chapter 3: Serial Interfacing With Microprocessor Based System

- Asked in: 2070 Chaitra, 2 marks; 2069 Chaitra, 3 marks; 2075 Asoj, 1 marks (asked 3 times)
- Video: [USB Protocol Explained: Basics, Versions, Connectors, Working, Signals, and Objectives](https://www.youtube.com/watch?v=6knlPjpa_DE) — Engineering Funda
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/instrumentation_ii/usb11-vs-usb20
- Whole chapter: https://www.bctengineer.com/md/semester_5/instrumentation_ii/chapter-3

## Question

Compare the USB standards USB 1.0/1.1 and USB 2.0.

## Short answer

USB 2.0 adds high speed 480 Mbps while keeping low and full speeds. It uses 125 µs microframes, bulk packet up to 512 bytes, high‑speed hubs with transaction translators, and PING protocol, whereas USB 1.1 max speed is 12 Mbps with 1 ms frames and 64‑byte bulk limit.

## Answer

| Feature | USB 1.0 / 1.1 | USB 2.0 |
|---|---|---|
| Year | 1996 / 1998 | 2000 |
| Speeds | Low speed 1.5 Mbps, full speed 12 Mbps | Low 1.5, full 12, **high speed 480 Mbps** |
| Frame time | 1 ms frames | 1 ms frames split into 125 us microframes in high speed |
| Packet size (bulk) | 64 bytes max | 512 bytes (high speed) |
| Transfer types | Control, bulk, interrupt, isochronous | Same four types, with split transactions and PING added |
| Hubs | Low/full speed hubs; no transaction translator needed | High speed hubs with transaction translator (TT) |
| Backward compatibility | - | Works with 1.1 devices and cables |
| Cable | 4 wires, shielded, 5 m max (full speed) | Same cable; maximum length 5 m |
| Added features | - | OTG supplement, better power management |
| Typical use | Keyboard, mouse, printers | Flash drives, cameras, external disks |

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What new speed does USB 2.0 add?
   A. 1.5 Mbps
   B. 12 Mbps
   C. 480 Mbps
   D. 5 Gbps
   Answer: C. USB 2.0 adds high speed 480 Mbps; 1.5 and 12 Mbps remain. (Key point: High speed)

2. How are frames handled in USB 2.0 high speed?
   A. 10 ms frames
   B. 1 ms frames split into 125 us microframes
   C. No frames
   D. Frames removed
   Answer: B. Frames remain 1 ms but are split into 125 us microframes. (Key point: Microframes)

3. What is the max bulk packet size at high speed?
   A. 64 bytes
   B. 128 bytes
   C. 512 bytes
   D. 1024 bytes
   Answer: C. USB 1.1 is 64 bytes; USB 2.0 high speed is 512 bytes. (Key point: Bulk packet size)

## Related in Instrumentation II

- [USB standards and data transfer mechanisms](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ausb-standards-transfer-mech) — Instrumentation II, chapter 3
- [USB interface chips: device vs host](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ausb-interface-chips) — Instrumentation II, chapter 3
- [USB enumeration; device vs host interface chips](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ausb-enumeration) — Instrumentation II, chapter 3
- [USB 1.1 vs 2.0 and device identification](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ausb11-vs-usb20-identify) — Instrumentation II, chapter 3
- [USB to RS-422 cable design](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ausb-rs422-cable) — Instrumentation II, chapter 3
- [Basic data transfer mechanisms in USB](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ausb-transfer-mechanisms) — Instrumentation II, chapter 3

## Related in other subjects

- [Comparison of 1G to 4G mobile standards](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3Agenerations-1g-to-4g-comparison) — Wireless Communication, chapter 1, asked 6×
- [Power screw threads, standards and materials](https://www.bctengineer.com/question.md?key=semester_7%2Fmachine_design_ii%3Ascrew-thread-types-standards-stress) — Machine Design II, chapter 8
- [Compare MOCB/BOCB and ABCB/puffer SF6](https://www.bctengineer.com/question.md?key=semester_6%2Fswitchgear_and_protection%3Acompare-mocb-bocb-abcb-sf6) — Switchgear and Protection, chapter 6