MIC2584/2585
Micrel
VCC2 1
SENSE2 2
GATE2 3
OV2 4
24 VCC1
23 SENSE1
22 GATE1
21 OV1
20 OUT1
19 DIS1
18 FB1
17 PG1
16 PG2
15 /POR
14 /FAULT
13 GND
Pin Configuration
VCC2 1
SENSE2 2
GATE2 3
OUT2 4
FB2 5
ON 6
CPOR 7
CFILTER 8
16 VCC1
15 SENSE1
14 GATE1
13 OUT1
12 FB1
11 /POR
10 /FAULT
9 GND
OUT2 5
DIS2 6
FB2 7
ON 8
TRK 9
CPOR 10
CFILTER 11
CDLY 12
MIC2584
16-Pin TSSOP (TS)
MIC2585
24-Pin TSSOP (TS)
Pin Description
Pin Number
MIC2584
16
Pin Number
MIC2585
24
Pin Name
VCC1
Pin Function
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.
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.
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.
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.
1
1
VCC2
2, 15
2, 23
SENSE2, SENSE1
6
8
ON
March 2005
3
MIC2584/2585
MICREL [ MICREL SEMICONDUCTOR ]
