Datasheet

Data Sheet ADM1075
Rev. B | Page 11 of 52
PIN CONFIGURATION AND FUNCTION DESCRIPTION
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VIN
UVH
UVL
VCAP
PLIM
OV
DRAIN
GATE
SENSE+
SENSE–
ADC_AUX
SPLYGD
VEE
A
DC_V
ISET
SS
ADR
SHDN
LATCH
TIMER
PWRGD
SCL
SDAI
GPO1/ALERT1/CONV
RESTART
GPO2/ALERT2
SDAO
VEE_G
TOP VIEW
(Not to Scale)
ADM1075
09312-004
Figure 3. TSSOP Pin Configuration
NOTES
1. EXPOSED PAD. SOLDER THE EXPOSED PAD TO THE BOARD TO
IMPROVE THERMAL DISSIPATION. THE EXPOSED PAD CAN BE
CONNECTED TO VEE.
1OV
2PLIM
3VCAP
4ADC_V
5ISET
6SS
7TIMER
17 PWRGD
18 ADC_AUX
19 SPLYGD
20 VEE
21 SENSE–
16 SCL
15 SDAI
8
LATCH
9
ADR
10
SHDN
11
RESTA
RT
12
GPO1/ALERT1/CONV
13
GPO2/ALERT2
14
SDAO
24
VEE_G
25
DRAIN
26
VIN
27
UVH
28
UVL
23
GATE
22
SENSE+
09312-003
TOP VIEW
(Not to Scale)
ADM1075
Figure 4. LFCSP Pin Configuration
Table 5. Pin Function Descriptions
Pin No.
TSSOP LFCSP Mnemonic Description
1 25 DRAIN
Connect to the drain pin of the FET through a resistor. The current in this resistor is used to determine
the V
DS
of the MOSFET. This is used for PWRGD.
2 26 VIN
Shunt Regulated Positive Supply to Chip. Connect to the positive supply rail via a shunt resistor. A
1 μF capacitor to VEE is recommended on the VIN pin.
3 27 UVH
Undervoltage Rising Input Pin. An external resistor divider is used from the supply to this pin to allow
an internal comparator to detect if the supply is under the UVH limit.
4 28 UVL
Undervoltage Falling Input Pin. An external resistor divider is used from the supply to this pin to
allow an internal comparator to detect if the supply is under the UVL limit.
5 1 OV
Overvoltage Input Pin. An external resistor divider is used from the supply to this pin to allow an
internal comparator to detect if the supply is above the OV limit.
6 2 PLIM
The voltage on this pin is proportional to the V
DS
voltage of the FET. As the PLIM voltage changes, the
current limit automatically adjusts to maintain constant power across the FET.
7 3 VCAP
A capacitor with a value of 1 μF or greater should be placed on this pin to maintain good accuracy.
This is an internal regulated supply. This pin can be used as a reference to program the ISET pin
voltage.
8 4 ADC_V
This pin is used to read back the input voltage using the internal ADC. It can be connected to the OV
string or a separate divider.
9 5 ISET
This pin allows the current limit threshold to be programmed. The default limit is set when this pin is
connected directly to VCAP. Alternatively, using a resistor divider from VCAP, the current limit can be
adjusted to achieve a user defined sense voltage. An external reference can also be used.
10 6 SS
A capacitor is used on this pin to set the inrush current soft start ramp profile. The voltage on the soft
start pin controls the current sense voltage limit, allowing control over the inrush current profile.
11 7 TIMER
Timer Pin. An external capacitor, C
TIMER
, sets an initial timing cycle delay and a fault delay. The GATE
pin turns off when the voltage on the TIMER pin exceeds the upper threshold.
12 8
LATCH
This pin signals the device latching off after an overcurrent fault. This pin is also used to configure the
desired retry scheme. See the Hot Swap Fault Retry section for additional details.
13 9 ADR
PMBus Address Pin. This pin can be tied low, tied to VCAP, left floating, or tied low through a resistor
to set four different PMBus addresses.