DS1227
DS1227
KickStarter Chip
FEATURES
•
Provides
PIN ASSIGNMENT
VCCO2
VCCO3
VCCO1
PWRON
VDCO
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
VCCO4
MODE4
SENSE
INT/ACK
OSCEXT
BOOST
ON1
ON4
RXIN
RXOUT
step-up regulation and microenergy
management for battery-operated systems
DC out for system power
•
Converts +3V to +6V DC input power source to +5V
•
“Kickstarts” system power upon detection of external
stimuli:
-
-
-
-
Clock/calendar alarm
Sensor trip; such as from a photo diode
Incoming activity to a serial port
Any low-level signal transition
VDCI
GND
ON/OFF3
OFF1
ON2/OFF2
•
Shuts
down microcontroller power under software
control when operation complete
powering of system functions
•
Provides 3 auxiliary power outputs for independent
•
Allows design of “power on demand” systems
•
Insures maximum life of main power source
•
Ideally suited for DS5000-based systems
•
Available in 20-pin DIP or SOIC packages
•
Operating temperature range of –40°C to +85°C
20-Pin DIP (300 Mil)
See Mech. Drawing - Sect. 16, Pg. 1
VCCO2
VCCO3
VCCO1
PWRON
VDCO
VDCI
GND
ON/OFF3
OFF1
ON2/OFF2
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
VCCO4
MODE4
SENSE
INT/ACK
OSCEXT
BOOST
ON1
ON4
RXIN
RXOUT
20-Pin SOIC (300 Mil)
See Mech. Drawing - Sect. 16, Pg. 6
ORDERING INFORMATION
DS1227:
DS1227S:
20-Pin DIP
20-Pin SOIC
DESCRIPTION
The DS1227 Kickstarter is a unique CMOS circuit which
combines power conversion and microenergy manage-
ment functions for battery operated systems. Using its
integral DC-DC converter, the DS1227 supplies +5V on
demand from either a 3– or 6–volt battery input. The pri-
mary +5V output, typically tied to the microcontroller’s
V
CC
pin, is “kickstarted” on in response to any one of
several possible momentary, external signal transitions.
Two auxiliary +5V power supply outputs can then be in-
dependently enabled or disabled under software con-
trol. When the primary power supply output is disabled,
also under software control, the auxiliary power supply
outputs remain in the state selected. In this manner, in-
dividual portions of the system can be powered only
022698 1/20
DALLAS [ DALLAS SEMICONDUCTOR ]
