LTC3675EUFF#PBF Linear Technology, LTC3675EUFF#PBF Datasheet - Page 25

• Manufacturer Part Number: LTC3675EUFF#PBF
• Description: IC, PMIC, 1A, QFN-44
• Manufacturer: Linear Technology

Specifications of LTC3675EUFF#PBF

• Supply Voltage: 5.5V
• No. Of Step-down Dc - Dc Converters: 4
• No. Of Ldo Regulators: 1
• Digital Ic Case Style: QFN
• No. Of Pins: 44
• No. Of Regulated Outputs: 7
• Operating Temperature Range: -40°C To +125°C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

OPERATION
On start-up, all PGOOD outputs are unmasked and a power-
on reset will cause RSTB to be pulled low. Once all enabled
regulators have their output PGOOD for 200ms typical
(C
By masking a PGOOD signal, the RSTB or IRQB pin will
remain Hi-Z even though the output voltage of a regulator
may be below its PGOOD threshold. However, when the
status register is read back, the true condition of PGOOD
is reported.
UNDERVOLTAGE AND OVERTEMPERATURE
FUNCTIONALITY
The undervoltage (UV) circuit monitors the input supply
voltage and shuts down all enabled regulators if the input
voltage falls below 2.45V. The LTC3675 also provides a
user with an undervoltage warning, which indicates to the
user that the input supply voltage is approaching the UV
threshold. The undervoltage warning threshold is user
programmable as shown in Table 2.
Table 2. UV Warning Thresholds
UV[2], UV[1], UV[0]
000 (Default)
001
010
011
100
101
110
111
T
= 0.01μF) the RSTB output goes Hi-Z.
FALLING V
2.7V
2.8V
2.9V
3.0V
3.1V
3.2V
3.3V
3.4V
IN
WARNING THRESHOLD
To prevent thermal damage to the LTC3675 and its sur-
rounding components, the LTC3675 incorporates an
overtemperature (OT) function. When the LTC3675 die
temperature reaches 150°C all enabled regulators are shut
down and remain in shutdown until the die temperature falls
to 135°C. The LTC3675 also has an overtemperature warn-
ing function which warns a user that the die temperature
is approaching the OT threshold which allows the user to
take any corrective action. The OT warning threshold is
user programmable as shown in Table 3.
Table 3. OT Warning Thresholds
OT[1], OT[0]
00 (Default)
01
10
11
A UV or OT warning is reported to the user when the IRQB
pin is in its high impedance state. The UV and OT warning
fl ags are not maskable by the user.
RESET_ALL Functionality: The RESET_ALL bit shuts down
all enabled regulators (enabled either via its enable pin or
I
put in their default state.
2
C) for 1 second. All command registers are cleared and
OT WARNING THRESHOLD
10° Below OT
20° Below OT
30° Below OT
40° Below OT
LTC3675
25
3675f