Micropower, Low-Voltage, UCSP/SC70,

Rail-to-Rail I/O Comparators

_______________________________________________________________________________________

9

Zero-Crossing Detector

Figure 3 shows a zero-crossing detector application.

The MAX985’s inverting input is connected to ground,

signal source. As the signal at the noninverting input

crosses 0V, the comparator’s output changes state.

Logic-Level Translator

Figure 4 shows an application that converts 5V logic lev-

els to 3V logic levels. The MAX986 is powered by the 5V

supply voltage, and the pullup resistor for the MAX986’s

open-drain output is connected to the 3V supply voltage.

This configuration allows the full 5V logic swing without

creating overvoltage on the 3V logic inputs. For 3V to 5V

logic-level translation, simply connect the 3V supply to

UCSP Package Consideration

For general UCSP package information and PC layout

considerations, please refer to Maxim Application

Note,“Wafer-Level Chip-Scale Package.”

UCSP Reliability

The chip-scale package (UCSP) represents a unique

packaging form factor that may not perform equally to a

packaged product through traditional mechanical relia-

bility tests. UCSP reliability is integrally linked to the

user’s assembly methods, circuit board material, and

usage environment. The user should closely review

these areas when considering use of a UCSP package.

Performance through Operating Life Test and Moisture

Resistance remains uncompromised as it is primarily

determined by the wafer-fabrication process.

Mechanical stress performance is a greater consideration

for a UCSP package. UCSPs are attached through direct

solder contact to the user’s PC board, foregoing the

inherent stress relief of a packaged product lead frame.

Solder joint contact integrity must be considered.

Information on Maxim’s qualification plan, test data, and

recommendations are detailed in the UCSP application

note, which can be found on Maxim’s website at

www.maxim-ic.com.

MAX985

IN+

4

3

OUT

1

2

5

100mV

IN-

MAX986

IN-

100k

Ω

100k

Ω

4

3

3V (5V)

LOGIC OUT

OUT

1

5

2

5V (3V)

3V (5V)

5V (3V) LOGIC IN

IN+

Figure 3. Zero-Crossing Detector

Figure 4. Logic-Level Translator