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dc2118af

DEMO MANUAL DC2118A

QUICK START PROCEDURE

Figure 3. Proper Measurement Equipment Setup

11. Total backup runtime is based on battery capacity,

circuit efficiency, and system load. Figure 2 shows an

exampledischargecurvewithconstantcurrentsystem

load.

12. WhenVSYSfallsbelow7.5%oftheprogrammedvalue,

or 4.6V, then RST will toggle on.

Optional

1. UseanexternalthermistorconnectedbetweenEXTNTC

and GND as shown in Figure 3, with the NTC jumper,

JP1, set to EXT.

2. Change the setting of the ENCHG, JP2, or ENBST, JP3,

jumpers to enable/disable charging and backup boost

respectively.

3. Monitor the PROG pin voltage for a scaled representa-

tion of the instantaneous charge current according to

the relationship:

4. MonitortheCLPROGpinvoltageforascaledrepresenta-

tion of the instantaneous total input current according

to the relationship:

5. All status LEDs can be disconnected to reduce the

quiescent current by setting the LEDS jumper, JP6 to

OFF.

6. External VDD can be used by connecting to EXTVDD

and installing 0Ω for R16.

+

Table 1. Battery Charge Voltage Jumper Settings

JP7

JP5

JP4

F1

F0

3.95

3.45

0

0

4.00

3.50

0

1

4.05

3.55

1

0

4.10

3.60

1

1