BL8598

BL8598
Adjustable Overvoltage Protector with High Accuracy
DESCRIPTION
FEATURES
The BL8598 overvoltage protection devices
feature a low 180
(typ) RON internal FET and
safeguards 2.2V to 28V systems from power
supply overvoltage. If the input voltage exceeds
the overvoltage threshold, the internal FET is
turned off to prevent the output load circuits
from damage.
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The overvoltage protection threshold can be
adjusted with optional external resistors to any
voltage between 4V and 8V. With the OVLO input
set below the external OVLO select voltage, the
BL8598 automatically choose the internal ±2.5%
accurate trip thresholds. The internal overvoltage
thresholds (OVLO) are preset to 6.75V typical.
The BL8598 includes an internal thermal
shutdown circuit which can protect against
overcurrent events.
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Overvoltage Protection up to 28V
±2.5% Accurate 6.75V OVLO Threshold
Adjustable Overvoltage Protection Trip Level
Integrated 180
n-Channel MOSFET Switch
Automatic Overvoltage Protection Trip-Level
Selection
Internal 15ms Startup Delay
Thermal Shutdown Protection
Available in DFN2x2-8L Package
Temperature Range: -40C~85C
APPLICATIONS
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Cell Phones
MP3 and MP4 players
PDAs and Palmtop Devices
BL8598 is available in DFN2x2-8L package.
TYPICAL APPLICATION
PIN OUT
BL8598
R1 and R2 are required only for adjustable OVLO;
otherwise, connect OVLO to GND.
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DFN2x2-8L
*Connect exposed PAD to GND.
BL8598
ABSOLUTE MAXIMUM RATING
Parameter
Value
Max Input Voltage
VOUT
OVLO
Continuous VIN Current
Peak VIN Current (Note 1)
Continuous OVLO Current
Max Operating Junction Temperature(TJ)
Ambient Temperature(TA)
Thermal resistance: ΘJA
Storage Temperature(TS)
Lead Temperature & Time
30V
-0.3V – VIN + 0.3V
-0.3V – 6V
1A
5A
50uA
125C
-40C – 85C
76.5°C/W
-40C - 150C
260C, 10S
Note1: Limited by thermal shutdown.
Note2: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect device
reliability.
ELECTRICAL CHARACTERISTICS
(VIN=5V, TA=25C)
Symbol
VIN
IIN
IQ
VIN_OVLO
VIN_OVLO_HYS
VOVLO_THRESH
VOVLO_SELECT
VOVLO_HYS
RON
tINDBC
Parameter
Conditions
Input Voltage Range
Input Supply Current
Standby Current
Overvoltage Trip Level
Overvoltage Hysteresis
OVLO Set Threshold
External OVLO Select Threshold
External OVLO Select Hysteresis
Switch On-Resistance
OVLO Clamp
Thermal Shutdown
Thermal Hysteresis
Debounce time
tON
Switch Turn-On Time
tOFF
Switch Turn-Off Time
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Min
Typ
2.2
VIN < OVLO
VIN rising
ICLAMP = 10uA
145
Time from 1.6V < VIN <
VIN_OVLO to VOUT = 10% of VIN
1.6V < VIN < VIN_OVLO, RLOAD =
100 , CLOAD = 100uF; VOUT
from 10% to 90% of VIN
VIN > VOVLO_THRESH to VOUT =
80% of VIN_OVLO; RLOAD = 1K ,
VIN rising at 2V/100ns
2
Max
28
65
25
6.75
0.8
1.24
0.3
20
180
5.3
150
16
Unit
V
uA
uA
V
%
V
V
mV
250
V
15
ms
0.5
ms
1.7
us
BL8598
TIMING DIAGRAM
FUNCTION DIAGRAM
VOUT
VIN
Regulator
Charge Pump
Band Gap
OSC
Current Bias
CLK
EN
CLK
Timing
(15ms)
RESET
1.24V
OVP
OVLO
OTP
0.3V
SEL
Selection
PIN DESCRIPTION
PIN
NAME
1, 2
VIN
3
OVLO
4, 5
6
7, 8
I.C.
GND
VOUT
—
EP
DESCRIPTION
Supply voltage. Connect 10uF capacitor from VIN to GND. Connect all the VIN PINs together for proper operation.
External OVLO Adjustment. Connect OVLO to GND when using the internal threshold.
Connect a resistor-divider to OVLO to set a different OVLO threshold; this external resi
stor-divider is completely independent from the internal threshold.
Internally connected. Don’t connect. Leave I.C. unconnected.
Ground
Output voltage. Connect all the VOUT PINs together for proper operation.
Exposed pad. Connect exposed pad to ground. For enhanced thermal dissipation, connect EP to a copper area as large as possible. Don’t use EP as a sole ground connect.
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BL8598
TYPICAL PERFORMANCE CHARACTERISTICS
TA=25°C unless specified.
Normalized Ron vs.
Temperature
90
80
70
60
50
40
30
20
10
0
T=-40℃
T=+25℃
T=+85℃
0
2
Nromalized Ron
Supply Current(uA)
Supply Current vs. VIN
4
6
VIN(V)
8
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
-50
10
Normalized Debounce Time
Nromalized OVLO Threshold
1.03
1.01
0.99
0.97
0.95
0
25
50
75
100 125
Temperature(℃)
50
75
100
1.20
1.15
1.10
1.05
1.00
0.95
0.90
-50
-25
0
25
50
75
100 125
Temperature(℃)
Power-Up Response
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25
Normalized Debounce Time
vs. Temperature
1.05
-25
0
Temperature(℃)
Normalized OVLO Threshold
vs. Temperature
-50
-25
Overvoltage Rework Response
4
BL8598
DETAILED DESCRIPTION
APPLICATION INFORMATION
BL8598 overvoltage protection devices feature a
low 180
(typ) RON internal FET and
safeguards 2.2V to 28V systems from power
supply overvoltage. If the input voltage exceeds
the overvoltage threshold, the internal FET is
turned off to prevent the output load circuits
from damage. The 15ms debounce time
guarantees proper turn on of the internal FET
during startup.
VIN Bypass Capacitor
Device Operation
A 10uF ceramic capacitor is typically recommended
for CIN. CIN should be located as close to the device
VIN pin as practically possible. If the power source
has significant inductance due to long lead length,
take care to prevent overshoots due to the LC tank
circuit and provide protection if necessary to
prevent exceed- ing the +30V absolute maximum
rating on VIN.
Output Capacitor
On initial power up, if VIN > VOVLO_THRESH, VOUT is
disconnected from VIN. If VIN < VOVLO_THRESH, the
internal charge pump is enabled, the device enters
startup after a 15ms debounce delay.
Internal Switch
BL8598 incorporate an internal FET with a 180
RON. The FET is internally driven by a charge pump
that generates a necessary gate voltage above VIN.
The internal FET is capable of passing more than 5A
inrush current.
Overvoltage Lockout(OVLO)
BL8598 has a 6.75V OVLO threshold.
A 10uF output capacitor is required at the output.
External OVLO Adjustment Functionality
If OVLO is connected to ground, the internal OVLO
comparator uses the internally set OVLO value.
If OVLO is connected to the external resistor divider,
and VOVLO exceeds the OVLO select voltage,
VOVLO_SELECT, the internal OVLO comparator is
programmed with two resistors, R1 and R2. A
suggested value for R1 is
for minimum
current consumption. In the case of
and since VIN_OVLO, VOVLO_THRESH, R2 can be
approximated by the following formula:
Thermal Shutdown Protection
BL8598 has a thermal shutdown circuitry to turn off
the internal FET when the junction temperature
exceeds
. The FET will recover automatically
when the junction temperature falls by
.
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This external resistor divider is completely
independent from the internal resistor divider.
BL8598
PACKAGE OUTLINE
Package
DFN2x2-8L
Package specification：
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Devices per reel
6
3000Pcs
Unit
mm