19-5135; Rev 2; 3/12
TION KIT
EVALUA BLE
AVAILA
Integrated Charger, Dual Main Step-Down
Controllers, and Dual LDO Regulators
General Description
The MAX17085B is an all-in-one notebook power solution
integrating a multichemistry battery charger, dual fixed-
output Quick-PWMK step-down controllers, and dual
keep-alive linear regulators:
Charger:
The high-frequency (~1.4MHz) multichem-
istry battery charger uses a current-mode, fixed
inductor current ripple architecture that significantly
reduces component size and cost. Low-offset sense
amplifiers allow the use of low-value sense resistors
for charging and input current limit.
The charger uses n-channel switching MOSFETs.
Adjustable charge current, charge voltage, and cell
selection allow for flexible use with different battery
packs. Charge current is set by an analog control input,
or a PWM input. High-accuracy current-sense ampli-
fiers provide fast cycle-by-cycle current-mode control to
protect against short circuits to the battery and respond
quickly to system load transients. Additionally, the char-
ger provides a high-accuracy analog output that is pro-
portional to the adapter current.
An integrated charge pump controls an n-channel
adapter selector switch. The charge pump remains
active even when the charger is off. When the adapter
is absent, a p-channel MOSFET selects the battery.
Main SMPS:
The dual Quick-PWM step-down con-
trollers with synchronous rectification generate
the 5V and 3.3V main power in a notebook. Low-
side MOSFET sensing provides a simple low-cost,
highly efficient valley current-limit protection. The
MAX17085B also includes output undervoltage, out-
put overvoltage, and thermal-fault protection.
Separate enable inputs for each SMPS and a com-
bined open-drain power-good output allow flex-
ible power sequencing. Voltage soft-start reduces
inrush current, while passive shutdown discharges
the output through an internal switch. Fast transient
response, with an extended on-time feature reduces
output capacitance requirements. Selectable pulse-
skipping mode and ultrasonic mode improve light-
load efficiency. Ultrasonic mode operation maintains
a minimum switching frequency at light loads, mini-
mizing audible noise effects.
Dual LDO Regulators:
An internal 5V/100mA LDO5 with
switchover can be used to either generate the 5V bias
needed for power-up or other lower power “always-on”
suspend supplies. Another 3.3V/50mA LDO3 provides
“always-on” power to a system microcontroller.
Features
S
All-in-One Charger Plus Dual Main Step-Down
Controllers
S
5V/100mA and 3.3V/50mA LDO Regulators
S
Main
Dual Quick-PWM with Fast Transient Response
and Extended On-Time
300kHz to 800kHz Switching Frequency
Fixed 5V and 3.3V SMPS Outputs
Low-Noise Ultrasonic Mode
Autoretry Fault Protection
S
Charger
High Switching Frequency (1.4MHz)
Selectable 2-, 3-, and 4-Cell Battery Voltage
Automatic Selection of System Power Source
Internal Charge-Pump for Adapter n-Channel
MOSFETs Drive
Q0.4%
Accurate Charge Voltage
Q2.5%
Accurate Input Current Limiting
Q3%
Accurate Charge Current
S
Monitor Outputs for
AC Adapter Current (Q2% Accuracy)
Battery Discharge Current (Q2% Accuracy)
AC Adapter OK
S
Analog/PWM (100Hz to 500kHz) Adjustable
Charge Current Setting
S
AC Adapter Overvoltage and Overcurrent
Protection
MAX17085B
Applications
Notebook Computers
PDAs and Mobile Communicators
5V and 3.3V Supplies
2-to-4, Li+-Cell, Battery-Powered Devices
Ordering Information
PART
MAX17085BETL+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
40 TQFN-EP*
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Pin Configuration appears at end of data sheet.
Quick-PWM is a trademark of Maxim Integrated Products, Inc.
_______________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Integrated Charger, Dual Main Step-Down
Controllers, and Dual LDO Regulators
MAX17085B
ABSOLUTE MAXIMUM RATINGS (Note 1)
TON, DCIN, CSSP, BATT, CSIP to GND,
LX_ to GND ........................................................-0.3V to +28V
CSIP to CSIN, CSSP to CSSN ..............................-0.3V to +0.3V
LDO3, LDO5, VCC to GND (Note 2) .......................-0.3V to +6V
ISET, VCTL, ACIN,
ACOK
to GND ..........................-0.3V to +6V
OUT3, OUT5 to GND (Note 2) ................................-0.3V to +6V
ON3, ON5, PGOOD to GND ...................................-0.3V to +6V
ILIM3, ILIM5, SKIP, REF to GND .............. -0.3V to (V
CC
+ 0.3V)
GND to EP ............................................................-0.3V to +0.3V
DL_ to EP...............................................-0.3V to (V
LDO5
+ 0.3V)
BST_ to GND .........................................................-0.3V to +34V
BST_ to LDO5........................................................-0.3V to +28V
DH3 to LX3 ............................................ -0.3V to (V
BST3
+ 0.3V)
BST3 to LX3.............................................................-0.3V to +6V
DH5 to LX5 ............................................ -0.3V to (V
BST5
+ 0.3V)
BST5 to LX5.............................................................-0.3V to +6V
DHC to LXC ........................................... -0.3V to (V
BSTC
+ 0.3V)
PDSL to GND .......................................................-0.3V to + 36V
BSTC to LXC ...........................................................-0.3V to +6V
CELLS, CC, IINP to GND ......................-0.3V to (V
LDO5
+ 0.3V)
LDO_ Short Circuit to GND ....................................... Momentary
LDO5 Current (Internal Regulator) Continuous............. +100mA
LDO3 Current (Internal Regulator) Continuous............... +50mA
LDO_ Current (Switched Over) Continuous .................. +200mA
Continuous Power Dissipation (T
A
= +70NC)
40-Pin Thin QFN (derate 34.5mW/NC above +70NC) 2857mW
Operating Temperature Range .......................... -40NC to +85NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
Note 1:
Absolute Maximum Ratings valid using 20MHz bandwidth limit.
Note 2:
LDO5 has a weak leakage to V
CC
when LDO5 is more than 0.5V above V
CC
. OUT5 has a weak leakage to V
CC
when
OUT5 is more than 0.5V above V
CC
.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, no load on LDO5, LDO3, OUT5, OUT3, and REF, V
CC
= 5V, ON3 = ON5 = V
CC
, V
DCIN
= V
LXC
= V
CSSP
= V
CSSN
= 19V, V
BSTC
- V
LXC
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 12.6V, V
VCTL
= V
ISET
= 1.8V, CELLS = open,
T
A
= 0°C to +85°C,
unless oth-
erwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
INPUT SUPPLIES
Adapter Present Quiescent
Current
Charging
I
DCIN
+ I
CSSP
+ I
CSSN
,
enabled
ON3 = ON5 = SKIP = V
CC
,
V
OUT3
= 3.5V, V
OUT5
= 5.3V Charging
disabled
V
ISET
= 2.4V,
I
DCIN
+ I
CSSP
+ I
CSSN
,
IINP ON
ON3 = ON5 = SKIP = V
CC
,
V
OUT3
= 3.5V, V
OUT5
= 5.3V ISET = GND
V
CSSP
= V
CSSN
= 24V, T
A
= +25°C
V
BATT
= 16.8V, adapter absent, T
A
= +25°C
V
BATT
= 2V to 19V, adapter present
I
DCIN
ON3 = ON5 = SKIP = V
CC
, charger
disabled; V
OUT3
= 3.5V, V
OUT5
= 5.3V
V
DCIN
= 5V to 24V, ON3 = ON5 = GND
I
CC
ON3 = ON5 = SKIP = V
CC
, charger
disabled; V
OUT3
= 3.5V, V
OUT5
= 5.3V
Note:
LDO5 is NOT guaranteed to be in
regulation until DCIN is above 6V.
4.5
200
0.1
130
1.0
3
1.5
1.5
1.2
0.1
6
mA
2.5
2.5
2.2
2
4
650
0.2
270
1.5
24
FA
FA
mA
FA
mA
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Adapter Absent Quiescent
Current
CSSN Input Current
BATT + CSIP + CSIN + LXC
Input Current
DCIN Input Current
DCIN Standby Supply Current
V
CC
Supply Current
DCIN Input Voltage Range
mA
2
______________________________________________________________________________________
Integrated Charger, Dual Main Step-Down
Controllers, and Dual LDO Regulators
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, no load on LDO5, LDO3, OUT5, OUT3, and REF, V
CC
= 5V, ON3 = ON5 = V
CC
, V
DCIN
= V
LXC
= V
CSSP
= V
CSSN
= 19V, V
BSTC
- V
LXC
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 12.6V, V
VCTL
= V
ISET
= 1.8V, CELLS = open,
T
A
= 0°C to +85°C,
unless oth-
erwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DCIN Undervoltage-Lockout
Trip Point for Charger
DCIN POR Threshold
V
CC
Undervoltage Lockout
Threshold
V
CC
POR Threshold
LINEAR REGULATORS
V
LDO5
LDO_ Output-Voltage Accuracy
V
LDO3
Internal LDO Voltage After
Switchover
LDO3 Short-Circuit Current
LDO5 Short-Circuit Current
LDO5 Bootstrap Switch
Resistance
LDO3 Bootstrap Switch
Resistance
Thermal-Shutdown Threshold
REFERENCE
REF Output Voltage
REF Undervoltage-Lockout
Threshold
MAIN SMPS
OUT5 Output Voltage Accuracy
OUT3 Output Voltage Accuracy
Load Regulation Error
Line Regulation Error
V
OUT5
V
OUT3
V
IN
= 6V to 28V, SKIP = REF
V
IN
= 6V to 28V, SKIP = REF
Either SMPS, V
SKIP
= 2V, I
LOAD
= 0 to 5A
Either SMPS, SKIP = GND, I
LOAD
= 0 to 5A
Either SMPS, SKIP = V
CC
, I
LOAD
= 0 to 5A
Either SMPS, V
IN
= 6V to 28V
V
IN
= 12V,
V
OUT5
= 5.0V (Note 3) R
TON
= 202kI
(800kHz + 10%)
R
TON
= 549kI
(300kHz + 10%)
1073
402
5.033
3.267
5.083
3.300
-0.1
-1.7
-1.5
0.005
1263
473
1452
ns
545
%/V
%
5.135
3.333
V
V
V
REF
V
REF_UVLO
I
REF
= 50FA
V
REF
falling
2.09
2.10
2.0
2.11
V
V
t
SHDN
V
LDO5
V
LDO3
V
DCIN
= 6V to 24V, ON5 = ON3 = GND
0mA < I
LDO5
< 100mA, ON5 = GND
V
LDO5
= 5V, I
LDO5
= 0A
0mA < I
LDO3
< 50mA, ON3 = GND
Not production tested
Not production tested
LDO3 = GND
LDO5 = GND
LDO5 to OUT5, V
OUT5
= 5V, I
LDO5
= 50mA
LDO3 to OUT3, V
OUT3
= 3.3V,
I
LDO3
= 50mA
Hysteresis = 50NC
4.90
3.23
4.4
2.7
50
100
1.0
1.5
+160
5.00
3.30
4.5
2.8
5.10
V
3.37
4.6
2.9
130
260
2.5
3
V
mA
mA
I
I
NC
SYMBOL
V
DCIN(UVLO)
V
DCIN(POR)
V
CC(UVLO)
V
DCIN
falling
V
DCIN
rising
Falling edge of V
DCIN
Falling edge of V
CC
, PWM disabled below
this threshold
Rising edge of V
CC
Falling edge of V
CC
3.8
CONDITIONS
MIN
7.0
TYP
7.2
7.7
2.0
4.0
4.2
1.5
V
4.3
7.9
MAX
UNITS
V
V
V
MAX17085B
DH5 On-Time
t
ON5
_______________________________________________________________________________________
3
Integrated Charger, Dual Main Step-Down
Controllers, and Dual LDO Regulators
MAX17085B
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, no load on LDO5, LDO3, OUT5, OUT3, and REF, V
CC
= 5V, ON3 = ON5 = V
CC
, V
DCIN
= V
LXC
= V
CSSP
= V
CSSN
= 19V, V
BSTC
- V
LXC
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 12.6V, V
VCTL
= V
ISET
= 1.8V, CELLS = open,
T
A
= 0°C to +85°C,
unless oth-
erwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
V
IN
= 12V,
V
OUT3
= 3.3V (Note 3) R
TON
= 202kI
(800kHz - 10%)
(Note 3)
Duty cycle > 50%; not for production test
t
SS
Rising edge on ON_
15
f
SW(USONIC)
SKIP = GND
R
TON
= 549kI
(300kHz - 10%)
MIN
866
325
210
TYP
1019
382
270
300
2
22
MAX
1171
ns
439
330
360
ns
ns
ms
kHz
UNITS
DH3 On-Time
t
ON3
Minimum Off-Time
Extended On-Time Blanking
Soft-Start Time
Ultrasonic Operating Frequency
OUT_ Overvoltage Trip
Threshold (PGOOD Pulled Low
Above This Level)
OUT_Overvoltage Fault
Propagation Delay
OUT_ Undervoltage Protection
Trip Threshold
OUT_ Output Undervoltage
Fault Propagation Delay
PGOOD Lower Trip Threshold
PGOOD Propagation Delay
PGOOD Output Low Voltage
MAIN SMPS FAULT DETECTION
t
OFF(MIN)
With respect to error comparator threshold
13
16
19
%
t
OVP
V
FB_
forced 50mV above trip threshold
With respect to error comparator threshold
65
10
70
10
75
Fs
%
Fs
-150
mV
Fs
0.3
V
t
UVP
With respect to error comparator threshold,
falling edge, hysteresis = 15mV
t
PGOOD
OUT5 or OUT3 forced 50mV beyond
PGOOD trip threshold, falling edge
PGOOD low impedance, ON5 = ON3 =
GND, I
SINK
= 4mA
I
PGOOD
PGOOD high impedance, SMPS in
regulation, PGOOD forced to 5.5V,
T
A
= +25°C
7
0.2
T
A
= +25°C
V
ILIM
_ = 0.5V
V
LIM
_
(VAL)
V
AGND
- V
LX
_
V
ILIM
_ = 1.00V
V
ILIM
_ = 2.10V
I
NEG(US)
V
ZX
V
AGND
- V
LX
_, SKIP = V
CC
or GND,
V
ILIM
= 1V
-0.1
40
87
184
-350
-250
10
PGOOD Leakage Current
Fault Reset Timer
MAIN SMPS CURRENT LIMIT
ILIM_ Adjustment Range
ILIM_ Leakage Current
Valley Current-Limit Threshold
(Adjustable)
Ultrasonic Negative
Current-Limit Threshold
Current-Limit Threshold
(Zero Crossing)
1
10
2.1
+0.1
50
100
210
72
1.5
60
113
236
FA
ms
V
FA
mV
mV
mV
4
______________________________________________________________________________________
Integrated Charger, Dual Main Step-Down
Controllers, and Dual LDO Regulators
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, no load on LDO5, LDO3, OUT5, OUT3, and REF, V
CC
= 5V, ON3 = ON5 = V
CC
, V
DCIN
= V
LXC
= V
CSSP
= V
CSSN
= 19V, V
BSTC
- V
LXC
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 12.6V, V
VCTL
= V
ISET
= 1.8V, CELLS = open,
T
A
= 0°C to +85°C,
unless oth-
erwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
High = SKIP
Mid = PWM
Low = ultrasonic
V
SKIP
= 0 or 5V, T
A
= +25°C
High (SMPS on)
Low (SMPS off)
V
ON3
= V
ON5
= 0 or 5V, T
A
= +25°C
R
DSCHG
ON_ = GND
-2
7.5
20
MIN
2.3
1.5
0
-2
2.4
0.8
+2
50
TYP
MAX
V
CC
1.9
0.8
+2
UNITS
MAIN SMPS INPUTS AND OUTPUTS
SKIP Threshold Voltage
SKIP Leakage Current
ON_ Input Logic Levels
ON_ Leakage Current
OUT_ Discharge-Mode
On-Resistance
SMPS GATE DRIVERS
DH3, DH5 Gate Driver
On-Resistance
DL3, DL5 Gate Driver
On-Resistance
DH3, DH5 Gate Driver Source/
Sink Current
DL3, DL5 Gate Driver
Source Current
DL3, DL5 Gate Driver
Sink Current
DHC Gate Driver On-
Resistance
DLC Gate Driver
On-Resistance
Internal BST_ Switch
On-Resistance
BST_ Leakage Current
CHARGER SMPS
DHC Off-Time K Factor
Sense Voltage for Minimum
Discontinuous Mode Ripple
Current
Zero Crossing Comparator
Threshold
Cycle-by-Cycle Current- Limit
Sense Voltage
V
DCIN
= 19V, V
BATT
= 10V
V
CSIP
- V
CSIN
V
CSIP
- V
CSIN
V
CSIP
- V
CSIN
120
30
35
5
10
125
130
40
ns/V
mV
mV
mV
BST3 - LX3 and BST5 - LX5 forced to 5V;
high state
BST3 - LX3 and BST5 - LX5 forced to 5V; low
state
DL3, DL5; high state
DL3, DL5; low state
DH3, DH5 forced to 2.5V,
BST3 - LX3 and BST5 - LX5 forced to 5V
1.6
1.6
1.5
0.6
2
1.7
3.3
1.5
0.8
3
3
5
2
20
3
2.1
6
6
3.8
I
3.8
3.5
1.5
I
A
A
A
I
I
I
FA
V
SKIP
V
FA
V
FA
I
MAX17085B
R
DH3
, R
DH5
R
DL3
, R
DL5
I
DH
I
DL(SOURCE)
DL3, DL5 forced to 2.5V
I
DL(SINK)
R
DHC
R
DLC
R
BST
I
BST
DL3, DL5 forced to 2.5V
High state, I
DHC
= 10mA
Low state, I
DHC
= -10mA
High state, I
DLC
= 10mA
Low state, I
DLC
= -10mA
I
BST
_ = 10mA, V
DD
= 5V
V
BST
_ = 24V, OUT3 and OUT5 above
regulation threshold, T
A
= +25°C
_______________________________________________________________________________________
5
MicroPython开源版块
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
