MAX8688EVKIT+ Maxim Integrated, MAX8688EVKIT+ Datasheet - Page 20
![no-image](/images/no-image-200.jpg)
MAX8688EVKIT+
Manufacturer Part Number
MAX8688EVKIT+
Description
Current & Power Monitors & Regulators DIGITAL POWER SUPPLY
Manufacturer
Maxim Integrated
Datasheet
1.MAX8688ALETGGH9.pdf
(38 pages)
Specifications of MAX8688EVKIT+
Product
Power Monitors
Supply Voltage - Max
3.6 V
Supply Voltage - Min
3 V
Operating Temperature Range
- 40 C to + 85 C
Input Voltage Range
3 V to 3.6 V
Digital Power-Supply Controller/Monitor
with PMBus Interface
In addition to providing address information to the
MAX8688, A3/ONOFF can also be used as a control sig-
nal for turning the POL on or off, similar to the OPERATION
command. To use A3/ONOFF to control the POL, config-
ure the A3 Control Enable bit in MFR_MODE command.
When A3 control is enabled, a transition of A3/ONOFF
from low to high turns the POL on, as if the MAX8688 has
received an OPERATION ON command. A transition of
A3/ONOFF from high to low initiates a soft-off to the POL
—as if the MAX8688 has received an OPERATION OFF
command (soft-off, with sequencing). The MAX8688 still
responds to the PMBus OPERATION command while
A3 control is enabled. To detect the A3/ONOFF input,
the A3/ONOFF signal pulse width has to satisfy the
t
disabled (cleared to 0), the MAX8688 ignores the
Figure 11. Application Diagram with A3/ONOFF as Both Address and On/Off Control Signal
20
A3_LOW
MAX8688_EN
HIZ_EN
______________________________________________________________________________________
and t
A3_HIGH
U1
U2
U3
requirement to be detected. If
33kΩ
33kΩ
A3/ONOFF Operation
3.3V
A3/ONOFF
A2/SDAE
A1/SCLE
A3/ONOFF
A2/SDAE
A1/SCLE
A3/ONOFF
A2/SDAE
A1/SCLE
MAX8688
MAX8688
MAX8688
REFO
REFO
REFO
1µF
1µF
1µF
HIZ_EN PLACES U1, U2, AND U3 OUTPUTS IN HIGH-IMPEDANCE STATE WHEN ASSERTED.
U1, U2, AND U3 ARE NOT NECESSARY IF AN EEPROM IS ATTACHED TO A1/SCLE AND A2/SDAE.
A1/SCLE, A2/SDAE ARE EITHER PULLED UP OR PULLED DOWN WITH 33kΩ WHEN CONNECTED
TO AN EEPROM.
MAX8688_EN
A3/ONOFF state and function as directed by the OPER-
ATION command only.
The dual functionality of A3/ONOFF of the MAX8688
requires the system enable signal to be isolated from
A3/ONOFF until the address setting has been read and
latched by the MAX8688. Figure 11 shows one imple-
mentation for the three possible states of the
A3/ONOFF setting. In each case, the system enable
signal (MAX8688_EN) is applied to the input of a three-
state buffer whose output is kept in the high-impedance
state by a control input signal (HIZ_EN) for a time peri-
od during which the MAX8688 reads and latches the
A3/ONOFF address setting. After this period, the con-
trol signal HIZ_EN goes low and allows the system
enable signal to be applied to the MAX8688 A3/ONOFF
pin. After a t
tions from low to high and causes the MAX8688s to
commence POL startup operations.
A3/ONOFF
HIZ_EN
AVDD
REFO
A3_LOW
t
RST_WAIT
, the MAX8688_EN signal transi-
t
A3_LOW
MAX8688_UVLO