6

FN6655.1

June 8, 2009

The ISL88042EVAL1Z and Applications

The ISL88042EVAL1Z supports all variants of the ISL88042

devices, enabling evaluation of basic functional operation and

common application implementations. Figure 10 illustrates the

ISL88042EVAL1Z in schematic and photographic forms. The

ISL88042EVAL1Z is populated with the ISL88042IRTEEZ

With adequate bias on the two preset and the two adjustable

monitor inputs the RST output will release to pull high

indicating that all supplies are compliant for a minimum of

V2MON nominal thresholds are as previously noted with the

voltage thresholds being monitored by V3MON and V4MON

being left open for programming via the non populated

resistor dividers.

Special Application Considerations

Using good decoupling practices on bias and other

monitoring inputs will prevent transients (i.e. due to switching

noises and short duration droops in the supply voltage) from

causing unwanted resets.

In unusually noisy environments or situations where

unwanted signals may be injected into the adjustable VMON

inputs, lowering the node impedance and/or positioning a

small valued filter capacitor as close to the pin as possible

can increase noise immunity.

Although the internal ISL88042 threshold references are

guaranteed over the full temp range, accuracy errors due to

external component tolerances and distribution losses will

occur. High tolerance resistors and layout for extreme

accuracy and critical performance must be considered.

Typical Performance Curves

FIGURE 4. VDD and V2MON Vth vs TEMPERATURE

FIGURE 5. V3MON and V4MON Vth vs TEMPERATURE

FIGURE 7. BIAS CURRENT vs TEMPERATURE

2.80

2.85

2.90

2.95

3.00

3.05

3.10

3.15

3.20

-40

-20

0

25

50

85

100

125

TEMPERATURE (°C)

4.53

4.54

4.55

4.56

4.57

4.58

4.59

4.60

ISL88042IRTHF VDD

ISL88042IRTHF V2MON

ISL88042IRTEE V2MON

ISL88042IRTEE VDD

592

593

594

595

596

597

598

599

600

601

602

-40

-20

0

25

50

85

100

125

TEMPERATURE (°C)

V4MON

V3MON

80

85

90

95

100

105

110

115

120

-40

-20

0

255085

100

125

TEMPERATURE (°C)

0

2

4

6

8

10

12

14

16

-40

-20

0

25

50

85

100

125

TEMPERATURE (°C)

VDD = 5V

V2MON = 3.3V

ISL88042