19-3504; Rev 2; 2/06
KIT
ATION
EVALU
BLE
AVAILA
2.2MHz, Dual-Output Buck or Boost Converter
with Internal Power MOSFETs
General Description
The MAX5073 is a dual-output DC-DC converter with inte-
grated high-side n-channel power MOSFETs. Each output
can be configured either as a buck converter or a boost
converter. The device is capable of operating from a wide
5.5V to 23V input voltage range. Each output is program-
mable down to 0.8V in the buck mode and up to 28V in
the boost mode with an output voltage accuracy of ±1%.
In the buck mode, converter 1 and converter 2 can deliv-
er 2A and 1A, respectively. The output switching frequen-
cy of each converter can be programmed from 200kHz to
2.2MHz to avoid harmonics in a radio power supply or to
reduce the size of the power supply. Each output oper-
ates 180° out-of-phase thus reducing input-capacitor rip-
ple current, size, and cost. A SYNC input facilitates
external frequency synchronization. Moreover, a CLKOUT
output provides out-of-phase clock signal with respect to
converter 2, allowing four-phase operation using two
MAX5073 ICs in master-slave configuration.
The MAX5073 includes an internal digital soft-start that
reduces inrush current, eliminates output-voltage over-
shoot, and ensures monotonic rise in output voltage
during power-up. The device includes individual shut-
down and a power-good output for each converter.
Protection features include output short-circuit protec-
tion for buck mode and maximum duty-cycle limit for
boost operation, as well as thermal shutdown.
The MAX5073 is available in a thermally enhanced 28-
pin thin QFN package that can dissipate 2.7W at +70°C
ambient temperature. The device is rated for operation
over the -40°C to +85°C extended, or -40°C to +125°C
automotive temperature range.
Features
♦
4.5V to 5.5V or 5.5V to 23V Input Supply
Voltage Range
♦
0.8V (Buck) to 28V (Boost) Output Voltage
♦
Two Independent Output DC-DC Converters
with Internal Power MOSFETs
♦
Each Output can be Configured in Buck or Boost
Mode
♦
I
OUT1
and I
OUT2
of 2A and 1A (Respectively) in
Buck Mode
♦
180° Out-of-Phase Operation
♦
Clock Output for Four Phase Operation
♦
Switching Frequency Programmable from 200kHz
to 2.2MHz
♦
Digital Soft-Start and Sync Input
♦
Individual Converter Shutdown and Power-Good
Output
♦
Short-Circuit Protection (Buck)/Maximum Duty-
Cycle Limit (Boost)
♦
Thermal Shutdown
♦
Thermally Enhanced 28-Pin Thin QFN Package
Dissipates up to 2.7W at +70°C
MAX5073
Pin Configuration
BST1/VDD1
PGOOD1
DRAIN1
DRAIN1
EN1
Applications
Automotive Radio Power Supply
Point-of-Load DC-DC Converters
Telecom Line Card
Networking Line Card
Power-Over-Ethernet Postregulation for PDs
PGOOD2
SOURCE1
SOURCE1
SGND
PGND
21
22
23
24
25
26
27
28
1
CLKOUT
20
19
18
17
16
FB1
TOP VIEW
15
14
13
12
BYPASS
VL
VL
V+
OSC
N.C.
SYNC
COMP1
Ordering Information
PART
MAX5073ETI
MAX5073ETI+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
PKG
CODE
MAX5073
11
10
9
8
SOURCE2
SOURCE2
28 Thin QFN-EP*
T2855-6
(5mm x 5mm)
28 Thin QFN-EP*
T2855-6
(5mm x 5mm)
2
BST2/VDD2
3
DRAIN2
4
DRAIN2
5
EN2
6
FB2
7
COMP2
*EP
= Exposed pad.
+Denotes
lead-free package.
Ordering Information continued at end of data sheet.
THIN QFN
1
________________________________________________________________
Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
2.2MHz, Dual-Output Buck or Boost Converter
with Internal Power MOSFETs
MAX5073
ABSOLUTE MAXIMUM RATINGS
V+ to PGND............................................................-0.3V to +25V
SGND to PGND .....................................................-0.3V to +0.3V
VL to SGND...................-0.3V to the lower of +6V or (V+ + 0.3V)
BST1/VDD1, BST2/VDD2, DRAIN_, PGOOD2, PGOOD1 to
SGND .................................................................-0.3V to +30V
BST1/VDD1 to SOURCE1,
BST2/VDD2 to SOURCE2 ....................................-0.3V to +6V
SOURCE_ to SGND................................................-0.6V to +25V
EN_ to SGND .............................................-0.3V to (VL to +0.3V)
CLKOUT, BYPASS, OSC, COMP1,
COMP2, SYNC, FB_ to SGND ..................-0.3V to (VL + 0.3V)
SOURCE1, DRAIN1 Peak Current ..............................5A for 1ms
SOURCE2, DRAIN2 Peak Current ..............................3A for 1ms
VL, BYPASS to SGND Short Circuit............................Continuous
Continuous Power Dissipation (T
A
= +70°C)
28-Pin Thin QFN (derate 21.3mW/°C above +70°C).....2758mW*
Package Junction-to-Case Thermal Resistance (θ
JC
).......2°C/W
Operating Temperature Ranges:
MAX5073ETI (T
MIN
to T
MAX
)............................-40°C to +85°C
MAX5073ATI (T
MIN
to T
MAX
) .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
*As
per JEDEC51 standard.
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
(V+ = VL = 5.2V or V+ = 5.5V to 23V, EN_ = VL, SYNC = GND, I
VL
= 0mA, PGND = SGND, C
BYPASS
= 0.22µF, C
VL
= 4.7µF (ceram-
ic), R
OSC
= 10kΩ (circuit of Figure 1), T
A
= T
J
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
SYSTEM SPECIFICATIONS
Input Voltage Range
Operating Supply Current
V+
I
Q
(Note 2)
VL = V+
VL unloaded, no switching, V
FB_
= 1V, V+ =
12V, R
OSC
= 60kΩ
EN_ = 0, PGOOD_ floating, V+ = 12V,
R
OSC
= 60kΩ (MAX5073ETI)
EN_ = 0, PGOOD_ floating, V+ = 12V,
R
OSC
= 60kΩ (MAX5073ATI)
Efficiency
STARTUP/VL REGULATOR
VL Undervoltage Lockout Trip
Level
VL Undervoltage Lockout
Hysteresis
VL Output Voltage
BYPASS OUTPUT
BYPASS Voltage
BYPASS Load Regulation
SOFT-START
Digital Ramp Period
Soft-Start Steps
Internal 6-bit DAC
2048
64
f
OSC
clock
cycles
steps
V
BYPASS
∆V
BYPASS
I
BYPASS
= 0, R
OSC
= 60kΩ (MAX5073ETI)
I
BYPASS
= 0, R
OSC
= 60kΩ (MAX5073ATI)
0
≤
I
BYPASS
≤
50µA, R
OSC
= 60kΩ
1.98
1.975
0
2.00
2.00
2
2.02
2.025
10
V
mV
VL
V+ = 5.5V to 23V, I
SOURCE
= 0 to 40mA
4.9
UVLO
VL falling
3.95
4.1
175
5.2
5.5
4.25
V
mV
V
η
V
OUT1
= 3.3V at 1.5A,
V
OUT2
= 2.5V at 0.75A
(f
SW
= 1.25MHz)
V+ = VL = 5V
V+ = 12V
V+ = 16V
5.5
4.5
2.2
0.6
0.6
82
80
78
%
23.0
5.5
4
1.2
mA
1.4
V
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V+ Standby Supply Current
I
STBY
2
_______________________________________________________________________________________
2.2MHz, Dual-Output Buck or Boost Converter
with Internal Power MOSFETs
ELECTRICAL CHARACTERISTICS (continued)
(V+ = VL = 5.2V or V+ = 5.5V to 23V, EN_ = VL, SYNC = GND, I
VL
= 0mA, PGND = SGND, C
BYPASS
= 0.22µF, C
VL
= 4.7µF (ceram-
ic), R
OSC
= 10kΩ (circuit of Figure 1), T
A
= T
J
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
VOLTAGE-ERROR AMPLIFIER
FB_ Input Bias Current
FB_ Input Voltage Set Point
I
B(EA)
0°C
≤
T
A
≤
+70°C
-40°C
≤
T
A
≤
+85°C
-40°C
≤
T
J
≤
+125°C (MAX5073ATI only)
0°C to +85°C
FB_ to COMP_
Transconductance
INTERNAL PMOSFETS
I
SWITCH
= 100mA,
V
BST1
/V
DD1
to V
SOURCE1
= 5.2V
(MAX5073ETI)
I
SWITCH
= 100mA,
V
BST1
/V
DD1
to V
SOURCE1
= 5.2V
(MAX5073ATI)
I
SWITCH
= 100mA,
V
BST1
/V
DD1
to V
SOURCE1
= 4.5V
(MAX5073ETI)
I
SWITCH
= 100mA,
V
BST1
/V
DD1
to V
SOURCE1
= 4.5V
(MAX5073ATI)
I
SWITCH
= 100mA,
V
BST2
/V
DD2
to V
SOURCE2
= 5.2V
I
SWITCH
= 100mA,
V
BST2
/V
DD2
to V
SOURCE2
= 4.5V
V
OUT1
= 3.3V, V+ = 12V (Note 3)
V
OUT2
= 2.5V, V+ = 12V (Note 3)
EN1 = 0V, V
DS
= 23V
EN2 = 0V, V
DS
= 23V
195
290
g
M
-40°C to +85°C
-40°C to +125°C (MAX5073ATI only)
0.792
0.788
0.788
1.25
1.2
1.2
0.8
0.8
0.8
2
2
2
250
0.808
0.812
0.812
2.70
2.9
2.9
mS
V
nA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX5073
195
330
mΩ
On-Resistance Converter 1
R
ON1
200
315
200
350
330
350
2
1
630
mΩ
690
A
A
10
10
µA
µA
On-Resistance Converter 2
R
ON2
Minimum Converter 1 Output Current
Minimum Converter 2 Output Current
Converter 1 MOSFET Leakage
Current
Converter 2 MOSFET Leakage
Current
I
OUT1
I
OUT2
I
LK1
I
LK2
INTERNAL SWITCH CURRENT LIMIT
Current-Limit Converter 1
Current-Limit Converter 2
I
CL1
I
CL2
V+ = 12V (MAX5073ETI)
V+ = 12V (MAX5073ATI)
MAX5073ETI
MAX5073ATI
2.3
2.3
1.38
1.38
3
3
1.8
1.8
4.3
4.6
2.10
2.20
A
A
_______________________________________________________________________________________
3
2.2MHz, Dual-Output Buck or Boost Converter
with Internal Power MOSFETs
MAX5073
ELECTRICAL CHARACTERISTICS (continued)
(V+ = VL = 5.2V or V+ = 5.5V to 23V, EN_ = VL, SYNC = GND, I
VL
= 0mA, PGND = SGND, C
BYPASS
= 0.22µF, C
VL
= 4.7µF (ceram-
ic), R
OSC
= 10kΩ (circuit of Figure 1), T
A
= T
J
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
INTERNAL OSCILLATOR/SYNC
Maximum Duty Cycle
Switching Frequency Range
Switching Frequency
Switching Frequency Accuracy
SYNC Frequency Range
SYNC High Threshold
SYNC Low Threshold
SYNC Input Min Pulse Width
Clock Output Phase Delay
SYNC to SOURCE1 Phase Delay
Clock Output High Level
Clock Output Low Level
EN_ INPUTS
EN_ Input High Threshold
EN_ Input Low Threshold
EN_ Bias Current
POWER-GOOD OUTPUT (PGOOD_)
PGOOD_ Threshold
PGOOD_ Output Voltage
PGOOD_ Output Leakage Current
THERMAL MANAGEMENT
Thermal Shutdown
Thermal Hysteresis
T
SHDN
T
HYST
Junction temperature
Junction temperature
+150
30
°C
°C
PGOODVTH
_
SYMBOL
CONDITIONS
SYNC = SGND, f
SW
= 1.25MHz
SYNC = SGND, f
SW
= 2.2MHz
Each converter
R
OSC
= 10kΩ, each converter
5.6kΩ
≤
R
OSC
≤
56kΩ, 1% each converter
SYNC input frequency is twice the
individual converter frequency
MIN
84
84
200
1125
-15
400
2.4
TYP
86
86
1250
MAX
95
95
2200
1375
+15
4400
UNITS
D
MAX
f
SW
f
SET
%
kHz
kHz
%
kHz
V
f
SYNC
V
SYNCH
V
SYNCL
t
SYNCIN
CLKOUT
PHASE
0.8
100
R
OSC
= 60kΩ, 1%, with respect to converter
2 / SOURCE2 waveform
VL = 5.2V, sourcing 5mA
VL = 5.2V, sinking 5mA
V+ = VL = 5.2V
V+ = VL = 5.2V
2.4
1.8
1.2
0.8
250
PGOOD goes high after V
OUT
crosses
PGOOD_ threshold
I
SINK
= 3mA (MAX5073ETI)
I
SINK
= 3mA (MAX5073ATI)
V+ = VL = 5.2V, V
PGOOD_
= 23V, V
FB_
= 1V
4
0.4
45
45
V
ns
degrees
degrees
V
V
V
V
nA
SYNC
PHASE
R
OSC
= 60kΩ, 1%
V
CLKOUTH
V
CLKOUTL
V
IH
V
IL
I
B(EN)
90
92.5
95
0.4
0.52
1
% V
OUT
V
µA
V
PGOOD_
I
LKPGOOD_
Note 1:
Specifications at -40°C are guaranteed by design and not production tested.
Note 2:
Operating supply range (V+) is guaranteed by VL line regulation test. Connect V+ to VL for 5V operation.
Note 3:
Output current may be limited by the power dissipation of the package, refer to the
Power Dissipation
section in the
Applications Information.
4
_______________________________________________________________________________________
2.2MHz, Dual-Output Buck or Boost Converter
with Internal Power MOSFETs
Typical Operating Characteristics
(V+ = VL = 5.2V, T
A
= +25°C, unless otherwise noted.)
OUTPUT1 EFFICIENCY (BUCK CONVERTER)
vs. LOAD CURRENT
MAX5073 toc01
MAX5073
OUTPUT2 EFFICIENCY (BUCK CONVERTER)
vs. LOAD CURRENT
MAX5073 toc02
OUTPUT2 EFFICIENCY (BOOST CONVERTER)
vs. LOAD CURRENT
90
80
EFFICIENCY (%)
70
60
50
40
30
V
IN
= 3.3V
V
IN
= 5V
MAX5073 toc03
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
V
OUT
= 3.3V
f
SW
= 2.2MHz
V
IN
= 16.0V
V
IN
= 12.0V
V
IN
= 5V
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.2
0.3
0.4
0.5
0.6
LOAD (A)
0.7
V
OUT
= 2.5V
f
SW
= 2.2MHz
0.8
V
IN
= 16.0V
V
IN
= 12.0V
V
IN
= 5V
100
20
10
0
0.02
0.08
LOAD (A)
V
OUT
= 12V
f
SW
= 2.2MHz
0.14
0.20
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD (A)
0.9 1.0
OUTPUT1 VOLTAGE (BUCK CONVERTER)
vs. LOAD CURRENT
MAX5073 toc04
OUTPUT2 VOLTAGE (BUCK CONVERTER)
vs. LOAD CURRENT
MAX5073 toc05
VL OUTPUT VOLTAGE
vs. CONVERTER SWITCHING FREQUENCY
5.45
5.40
5.35
VL (V)
5.30
5.25
5.20
V
IN
= 23V
BOTH CONVERTERS SWITCHING
MAX5073 toc06
3.40
2.60
5.50
OUTPUT1 VOLTAGE (V)
OUTPUT2 VOLTGE (V)
3.35
2.55
3.30
2.50
3.25
5.15
5.10
5.05
V
IN
= 5.5V
3.20
0
0.5
1.0
LOAD (A)
1.5
2.0
2.45
0
0.25
0.50
LOAD (A)
0.75
1.00
5.00
0.1
0.6
1.1
1.6
2.1
2.6
SWITCHING FREQUENCY (f
SW
) (MHz)
VL DROPOUT VOLTAGE vs. EACH CONVERTER
SWITCHING FREQUENCY
MAX5073 toc07
EACH CONVERTER SWITCHING FREQUENCY
vs. R
OSC
MAX5073 toc08
EACH CONVERTER SWITCHING FREQUENCY
vs. TEMPERATURE
SWITCHING FREQUENCY (f
SW
) (MHz)
MAX5073 toc09
0.35
0.30
DROPOUT VOLTAGE (V)
0.25
0.20
0.15
0.10
0.05
0
0
0.5
1.0
1.5
2.0
V
IN
= 4.5V
V
IN
= 5.5V
10
SWITCHING FREQUENCY (f
SW
) (MHz)
10
2.2MHz
1.25MHz
1
0.6MHz
0.3MHz
V
IN
= 5V
1
0.1
2.5
0
20
40
R
OSC
(kΩ)
60
80
SWITCHING FREQUENCY (f
SW
) (MHz)
0.1
-50
0
50
TEMPERATURE (°C)
100
150
_______________________________________________________________________________________
5
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