GE b30, Technical Reference Manual

Page: 34 / 252

B30 Patient Monitor
1-20
Document no
.
2044677-001
Smart batteries, battery charger and PMC communicate via SMBus (System Management Bus).
It is a two-wire interface closely resembling I2C. Smart battery controls the charging and
calculates and stores the capacity information as well as other battery related data. Batteries
can be charged when external DC or AC/DC voltage is present.
Block diagram of the power supplies is represented in following
Figure 8 DC/DC board block diagram
Battery charger
Battery charger is a Level 2 Smart Battery Charger. It communicates with the batteries and
PMC CPU via SMBus interface. The charger acts as an SMBus slave device that responds to
charging current and charging voltage values sent to it by a Smart Battery.
The charger includes an input current limiting feature. In a case where the input current
exceeds the limit, the charger reduces the output current to keep the input within the limit. The
currents of the MOD voltages (VMOD, I/O_VMOD) are taken through this current measurement
AC / DC
15.9V
+/-2%
SMART
BATTERY
CHARGER
(BUCK)
POWER
PATH
SWITCH
3.3V
BUCK
14.6V /
15.4V
2-LEVEL
BOOST
5V
BUCK
DC/DC BOARD FUNCTIONAL BLOCKS
VBOOST 14.1 - 16V
VSYS 9 - 16.2V
5V_PMC
PMC CPU
&
ON/STBY
LOGIC
SET_HI
2x BATTERY
10.8V Li-ION
(9-12.6V)
Boost converter
15.4V (set_hi)
14.6V
passed by diode Power source
@ EXTDC
@ Battery
@ AC/DC
CIRCUIT
BREAKER
= DC/DC-BOARD
EXTERNAL
DC
10 - 16.5V
SMART
BATTERIES
CIRCUIT
BREAKER
+3.3V +5V
VSYS_OUT
9 -16.2V
I/O_VMOD
13.8- 16V
VMOD
13.8 -16V
SERIAL COMM.
&
ON/STBY CTRL
POWER
PATH
SWITCH
CIRCUIT
BREAKER
+5V_OUT
dcdc_b
rd
_block
.v
sd