DS1227 Datasheet, PDF (1/20 Pages) Dallas Semiconductor – KickStarter Chip

DS1227
DS1227
KickStarter Chip
FEATURES
• Provides step-up regulation and microenergy
management for battery-operated systems
• Converts +3V to +6V DC input power source to +5V
DC out for system power
• “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
• Shuts down microcontroller power under software
control when operation complete
• Provides 3 auxiliary power outputs for independent
powering of system functions
• 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
PIN ASSIGNMENT
VCCO2 ₁
VCCO3 ₂
VCCO1 ₃
20 VCCO4
19 MODE4
18 SENSE
PWRON 4
17 INT/ACK
VDCO ₅
VDCI 6
16 OSCEXT
15 BOOST
GND 7
14 _ON1
ON/OFF3 ⁸
13 ON4
OFF1 9
12 _RXIN
ON2/OFF2 10
11 _RXOUT
20-Pin DIP (300 Mil)
See Mech. Drawing - Sect. 16, Pg. 1
VCCO2
VCCO3
1
20
VCCO4
2
19
MODE4
VCCO1
3
18 SENSE
PWRON
4
17
INT/ACK
VDCO
5
16
OSCEXT
VDCI
6
15
BOOST
GND
7
14
ON1
ON/OFF3
8
13
ON4
OFF1
9
12 RXIN
ON2/OFF2
10
11
RXOUT
20-Pin SOIC (300 Mil)
See Mech. Drawing - Sect. 16, Pg. 6
ORDERING INFORMATION
DS1227:
20-Pin DIP
DS1227S: 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