MAX17035(2009) Просмотр технического описания (PDF) - Maxim Integrated
Номер в каталоге
Компоненты Описание
производитель
MAX17035 Datasheet PDF : 27 Pages
| |||
High-Frequency,
Low-Cost SMBus Chargers
Table 1. EN Pin Function
ADAPTER
PRESENT
EN
PDSL STATUS
Yes
High
PDSL is pumped 8V above the DCIN
voltage (charge pump on).
Yes
Low
PDSL is pumped 8V above the DCIN
voltage (charge pump on).
No
High
Charge pump is off and PDSL is
forced to 0V (typ, 27C).
No
Low
Charge pump is off and PDSL is
forced to 0V (typ, 27C).
CHARGER STATUS
Enabled
Disabled
Disabled
Disabled
SYSTEM CURRENT MONITOR
STATUS (IINP PATH)
Enabled
Enabled
Enabled
Disabled
EN Pin
The EN pin is a logic input. The state of the EN pin and
the presence or absence of the adapter determines the
state of PDSL, the IINP path, and the charger function as
shown in Table 1.
30mA LDO
The 5.4V LDO is powered from DCIN and is compensated
for loads from 0 to 30mA with a single 1FF ceramic
capacitor. The load regulation over the 30mA load is
34mV (typ), 100mV max. The LDO supplies the drive for
the DLO driver and also the BST circuitry. It is shut down
when the adapter is absent.
Analog Input Current Monitor Output
IINP monitors the system-input current sensed across the
sense resistor (RS1) that connects between CSSP and
CSSN. The voltage at IINP is proportional to the input
current according to the following equation:
IINPUT
=
VIINP
RS1× A
where IINPUT is the DC current supplied by the AC
adapter and A is the gain (20V/V typ). IINP has a 0V to
2.2V output-voltage range.
Table 1 shows the charge and IINP status when the
adapter is present or absent and as a function of the
EN pin. When connected as shown in the standard
application circuit, IINP monitors the input system
current when the adapter is present or the battery
discharge current when the adapter is absent. Leave
IINP unconnected if not used.
Table 2 is the fault-protection and shutdown operation
table.
SMBus Implementation
The MAX17035/MAX17435/MAX17535 receive control inputs
from the SMBus interface. The MAX17035/MAX17435/
Table 2. Fault Protection and Shutdown
Operation Table
MODE
CONTROLLER
STATE
DRIVER
STATE
Thermal Fault
(Latched, Reset with
Adapter Insertion)
Charger
disabled
DHI and DLO
low
MAX17535 use a subset of the commands documented
in the System Management Bus Specifications V2.0,
which can be downloaded from www.smbus.org. The
MAX17035/MAX17435/MAX17535 use the SMBus read-
word and write-word protocols to communicate with the
system controller. The MAX17035/MAX17435/MAX17535
operate only as slave devices with address 0b0001001_
(0x12) and do not initiate communication on the bus. In
addition, the MAX17035/MAX17435/MAX17535 have
two identification registers: (0xFE), a 16-bit device ID
register and a 16-bit manufacturer ID register (0xFF).
The SMBus implementation is similar to the MAX8731A
with the addition of the RELEARN() and IINPVoltage()
commands. The SMBus is not powered from an external
supply, so during states that disable the charger, the
SMBus register data is lost, so the register data must be
rewritten when reenabled. See Figure 3.
The data (SDA) and clock (SCL) pins have Schmitt-
trigger inputs that can accommodate slow edges.
Choose pullup resistors for SDA and SCL to achieve rise
times according to the SMBus specifications.
Communication starts when the master signals a
START condition, which is a high-to-low transition on
SDA, while SCL is high. When the master has finished
communicating, the master issues a STOP condition,
which is a low-to-high transition on SDA, while SCL
is high. The bus is then free for another transmission.
16 �������������������������������������������������������������������������������������
Share Link: 