AN886 Datasheet, PDF (5/9 Pages) STMicroelectronics – A customer who develops an MCU-based application needs various levels of flexibility in order

SELECTING BETWEEN ROM, FASTROM AND OTP FOR A MICROCONTROLLER
3 TYPICAL MANUFACTURING LEAD TIME FOR ROM AND OTP
The complexity of all the operations needed to manufacture a component implies a certain
time period. Understanding STMicroelectronics’ MCU manufacturing cycle is important in
order to establish good relationships with customers. The numbers given here are typical and
subject to change in the future
Figure 2. Typical Fabrication Leadtime in weeks.
Transit Time**
7
5*
111
1
1
Wafer Fabrication
Standard Wafers*
Wafer
Probing
Assembly
Final Test
Shipment
*Pre-diffused Wafers (Selected Products)
**Wafer and assembly sites are typically located in different countries.
In order to limit lead time on ROM products, STMicroelectronics has introduced pre-diffusion
technology on selected products. This allows a two weeks reduction in total cycle time. Also
notice that MCU devices have to be ordered in specified minimum quantities for ROM version.
Figure 3. Typical Leadtime for Standard Products
12
12
Typical
Leadtime
for
Standard
Product
(weeks)
4
2*
Flash
4
FAST
ROM
10
Pre-
diffused
ROM
Standard
ROM
0 - 5,000 units
> 5,000 units
* Gold Standard products
> 5,000/10000 units
Min. Quantity
5/9