March 2005 3 MIC2584/2585
MIC2584/2585 Micrel
Pin Configuration
1VCC2
SENSE2
GATE2
OUT2
FB2
ON
CPOR
CFILTER
16 VCC1
SENSE1
GATE1
OUT1
FB1
/POR
/FAULT
GND
15
14
13
12
11
10
9
2
3
4
5
6
7
8
MIC2584
16-Pin TSSOP (TS)
CDLY GND1312
CFILTER /FAULT1411
1VCC2
SENSE2
GATE2
OV2
OUT2
DIS2
FB2
ON
TRK
CPOR
24 VCC1
SENSE1
GATE1
OV1
OUT1
DIS1
FB1
PG1
PG2
/POR
23
22
21
20
19
18
17
16
15
2
3
4
5
6
7
8
9
10
MIC2585
24-Pin TSSOP (TS)
Pin Description
Pin Number Pin Number Pin Name Pin Function
MIC2584 MIC2585
16 24 VCC1 Positive Supply (Input), Channel 1: This input is the main supply to the
internal circuitry and must be in the range of 2.3V to 13.2V. The GATE1 pin
is held low by an internal undervoltage lockout circuit until V
CC1
and V
CC2
exceed their respective undervoltage lockout threshold of 2.165V and 0.8V.
This input is protected up to 20V.
1 1 VCC2 Positive Supply (Input), Channel 2: The GATE2 pin is held low by an
internal undervoltage lockout circuit until V
CC1
and V
CC2
exceed their
respective undervoltage lockout threshold of 2.165V and 0.8V. This input
must be in the range of 1.0V to 13.2V and less than or equal to V
CC1
. This
input is protected up to 20V.
2, 15 2, 23 SENSE2, SENSE1 Circuit Breaker Sense (Inputs): A resistor between this pin and VCC1 and
VCC2 sets the current limit threshold for each channel. Whenever the
voltage across either sense resistor exceeds the slow trip current limit
threshold (V
TRIPSLOW
), the GATE voltage is adjusted to ensure a constant
load current. If V
TRIPSLOW
(50mV) is exceeded for longer than time period
t
OCSLOW
, then the circuit breaker is tripped and both GATE outputs are
immediately pulled low. If the voltage across either sense resistor exceeds
the fast trip circuit breaker threshold, V
TRIPFAST
, at any point due to fast,
high amplitude power supply faults, then both GATE outputs are immediately
brought low without delay. To disable the circuit breaker for either channel,
the SENSE and VCC pins can be tied together.
The default V
TRIPFAST
for either device is 100mV. Other fast trip thresholds
are available: 150mV, 200mV, or OFF (V
TRIPFAST
disabled). Please contact
factory for availability of other options.
6 8 ON Enable (Input): Active High. The ON pin, an input to a Schmitt-triggered
comparator used to enable/disable the controller, is compared to a 1.235V
reference with 25mV of hysteresis. When a logic high is applied to the ON
pin (V
ON
> 1.235V), a start-up sequence begins when the GATE1 and
GATE2 pins begin ramping up towards their final operating voltage. When
the ON pin receives a logic low signal (V
ON
< 1.21V), the GATE pins are
grounded and /FAULT remains high if both inputs are above their respective
UVLO thresholds. The ON pin must be low for at least 20µs in order to
initiate a start-up sequence. Additionally, toggling the ON pin LOW to HIGH
resets the circuit breaker.
