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General Description

The MAX17007/MAX17008 are dual Quick-PWM™ step-

down controllers intended for general power generation

in battery-powered systems. The two switched-mode

power supplies (SMPSs) can also be combined to oper-

ate in a two-phase single-output mode. Constant on-

time Quick-PWM operation provides fast response to

load transients and handles wide input/output (I/O) volt-

age ratios with ease, while maintaining a relatively con-

stant switching frequency. The switching frequency can

be individually adjusted between 200kHz and 600kHz

with external resistors. Differential output current sens-

ing allows output sense-resistor sensing for an accurate

current limit, or lossless inductor direct-current resis-

tance (DCR) current sensing for lower power dissipation

while maintaining 0.7% output accuracy. Overvoltage

(MAX17007 only), undervoltage protection, and accu-

rate user-selectable current limits (15mV, 30mV, 45mV,

and 60mV) ensure robust operations.

The SMPS outputs can operate in skip mode or in ultra-

sonic mode for improved light-load efficiency. The ultra-

sonic mode eliminates audible noises by maintaining a

minimum switching frequency of 25kHz in pulse-

skipping mode.

The output voltage of SMPS1 can be dynamically

adjusted by changing the voltage at the REFIN1 pin.

The device includes a 0.5% accurate reference output

that can be used to set the REFIN1 voltage. An external

5V bias supply is required to power the internal circuitry

and its gate drivers.

Independent on/off controls with well-defined logic thresh-

olds and independent open-drain power-good outputs

provide flexible system configurations. To prevent current

surges at startup, the internal voltage target is slowly

ramped up from zero to the final target with a slew rate of

1.3mV/µs for SMPS1 at CSL1 and 0.65mV/µs for SMPS2

at FB2. To prevent the output from ringing off below

ground in shutdown, the internal voltage target is ramped

down from its previous value to zero with the same

respective slew rates. Integrated bootstrap switches

eliminate the need for external bootstrap diodes.

The MAX17007/MAX17008 are available in a space-

saving, 28-pin, 4mm x 4mm, thin QFN package with an

exposed backside pad.

Applications

Features

 Dual Quick-PWM with Fast Transient Response

 Automatic Dynamic REFIN1 Detection and

PGOOD1/Fault Blanking

 Fixed and Adjustable Output Voltages

0.7% Output Accuracy Over Line and Load

OUT1: 0 to 2V Dynamic Output or Preset 1.05V

OUT2: 0.7V to 2V Range or Preset 1.5V

 Resistor-Programmable Switching Frequency

 Integrated BST Switches

 Differential Current-Sense Inputs

Low-Cost DCR Sensing or Accurate Current-

Sense Resistors

Internally Coupled Current-Sense Compensation

 Combinable Mode Supports High-Current

Dynamic Output Voltages

 Selectable Forced-PWM, Pulse Skip, or Ultrasonic

Mode Operation

 26V Maximum Input Voltage Rating

 Independent Enable Inputs

 Independent Power-Good Outputs

 Overvoltage Protection (MAX17007 Only)

 Undervoltage/Thermal Protection

 Automatic Dynamic REFIN1 Detection and

PGOOD1/Fault Blanking

 Voltage Soft-Start and Soft-Shutdown

MAX17007/MAX17008

Dual and Combinable QPWM Graphics

Core Controllers for Notebook Computers

________________________________________________________________

Maxim Integrated Products

MAX17007

MAX17008

THIN QFN

(4mm x 4mm)

1422

1223

1224

1125

1026

927

828

LX1

DH1

PGOOD1

EN1

CSH1

TOP VIEW

CSL1

REFIN1

LX2

DH2

PGOOD2

EN2

CSH2

CSL2

FB2

BST2

PGND

DL2

DL1

GND

BST1

REF

ILIM1

(CCI) ILIM2

SKIP

TON1

TON2

Pin Configuration

Ordering Information

19-3200; Rev 0; 2/08

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.

EVALUATION KIT

AVAILABLE

Denotes a lead-free package.

*Future product—contact factory for availability.

PART TEMP RANGE PIN-PACKAGE

MAX17007GTI+ -40°C to +105°C 28 Thin QFN

MAX17008GTI+* -40°C to +105°C 28 Thin QFN

Notebook Computers

Low-Power I/O Supplies

GPU Core Supplies

5V and 3.3V Supplies

2 to 4 Li+ Cells Battery-

Powered Devices

Quick-PWM is a trademark of Maxim Integrated Products, Inc.

Summary of content (35 pages)

PAGE 1
9-3200; Rev 0; 2/08 KIT ATION EVALU E L B A IL AVA Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Features The MAX17007/MAX17008 are dual Quick-PWM™ stepdown controllers intended for general power generation in battery-powered systems. The two switched-mode power supplies (SMPSs) can also be combined to operate in a two-phase single-output mode.
PAGE 2
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers ABSOLUTE MAXIMUM RATINGS BST1, BST2 to GND ...............................................-0.3V to +34V BST1, BST2 to VDD .................................................-0.3V to +28V TON1, TON2 to GND..............................................-0.3V to +28V VDD to GND ..............................................................-0.3V to +6V VDD to VCC ............................................................
PAGE 3
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers (VIN = 12V, VDD = VCC = EN1 = EN2 = 5V, VREFIN1 = 2V, SKIP = GND, TA = 0 to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN ILOAD = 0 to 3A, SKIP = VCC (Note 3) Load Regulation Error Line Regulation Error TYP MAX 0.1 UNITS % VDD = 4.5V to 5.5V, VIN = 4.5V to 26V (Note 3) 0.25 % CSL1 Soft-Start/-Stop Slew Rate SRSS1 Rising/falling edge on EN1 1.
PAGE 4
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers ELECTRICAL CHARACTERISTICS (continued) (VIN = 12V, VDD = VCC = EN1 = EN2 = 5V, VREFIN1 = 2V, SKIP = GND, TA = 0 to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS CURRENT LIMIT Current-Sense Input Range CSH1, CSH2 0 2.3 CSL1, CSL2 0 2.3 -0.2 +0.
PAGE 5
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers (VIN = 12V, VDD = VCC = EN1 = EN2 = 5V, VREFIN1 = 2V, SKIP = GND, TA = 0 to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 6
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers ELECTRICAL CHARACTERISTICS (continued) (VIN = 12V, VDD = VCC = EN1 = EN2 = 5V, VREFIN1 = 2V, SKIP = GND, TA = -40°C to +105°C, unless otherwise noted.) (Note 4) PARAMETER SYMBOL CONDITIONS REFIN1 Dual-Mode Switchover Threshold MIN MAX UNITS 3.75 VCC 0.4 V SMPS1 Voltage Accuracy VCSL1 Measured at CSL1, REFIN1 = VCC; VIN = 2V to 26V, SKIP = VCC (Note 2) 1.039 1.
PAGE 7
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers (VIN = 12V, VDD = VCC = EN1 = EN2 = 5V, VREFIN1 = 2V, SKIP = GND, TA = -40°C to +105°C, unless otherwise noted.) (Note 4) PARAMETER SYMBOL CONDITIONS MIN MAX UNITS GATE DRIVERS DH1, DH2 Gate Driver On-Resistance RON(DH) DL1, DL2 Gate Driver On-Resistance RON(DL) Driver Propagation Delay Internal BST_ Switch On-Resistance RBST_ BST_ - LX_ forced to 5V Low state (pulldown) 4.5 High state (pullup) 4.
PAGE 8
Typical Operating Characteristics (Circuit of Figure 1, VIN = 12V, VDD = 5V, SKIP = GND, TA = +25°C, unless otherwise noted.) 80 90 80 EFFICIENCY (%) 20V 12V 60 50 40 SKIP MODE 70 60 ULTRASONIC MODE 50 40 PWM MODE 30 SKIP MODE PWM MODE 1 100 10 0.01 0.1 1 10 0 100 5 15 10 COMBINED 1.2V EFFICIENCY vs. LOAD CURRENT COMBINED 1.2V OUTPUT VOLTAGE vs. LOAD CURRENT SMPS2 SWITCHING FREQUENCY vs. LOAD CURRENT 60 50 40 PWM 1.20 SKIP MODE 1.
PAGE 9
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers (Circuit of Figure 1, VIN = 12V, VDD = 5V, SKIP = GND, TA = +25°C, unless otherwise noted.) VIN = 12V 10 -20 0 20 40 60 ULTRASONIC MODE 2 SKIP MODE 0.01 4 8 12 16 4 24 20 6 8 10 12 14 16 18 20 22 24 REFIN1 TO CSL1 OFFSET VOLTAGE DISTRIBUTION SMPS1 PRESET 1.05V VOLTAGE DISTRIBUTION 80 1.95 SAMPLE SIZE = 100 TA = +85°C TA = +25°C 70 60 50 40 30 20 40 60 80 80 60 50 40 30 20 10 10 100 -5.0 -3.0 -1.
PAGE 10
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = 12V, VDD = 5V, SKIP = GND, TA = +25°C, unless otherwise noted.) SMPS1 STARTUP WAVEFORM SMPS1 STARTUP WAVEFORM (HEAVY LOAD) (LIGHT LOAD) MAX17007/8 toc19 5V 0 2V 0 1.05V 0 8A 5V 0 12V SMPS1 SHUTDOWN WAVEFORM MAX17007/8 toc21 MAX17007/8 toc20 A B C 5V 0 2V 0 1.05V A B C 5V 0 2V 1.
PAGE 11
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers (Circuit of Figure 1, VIN = 12V, VDD = 5V, SKIP = GND, TA = +25°C, unless otherwise noted.) DYNAMIC OUTPUT VOLTAGE TRANSITION (SKIP MODE) DYNAMIC OUTPUT VOLTAGE TRANSITION (PWM MODE) MAX17007/8 toc26 MAX17007/8 toc27 IOUT1 = 2A 1.2V DYNAMIC OUTPUT VOLTAGE TRANSITION (SKIP MODE-FORCED TRANSITION) MAX17007/8 toc28 1.2V 1.2V A 1V A 1V REFIN1 = 1V TO 1.
PAGE 12
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers MAX17007/MAX17008 Pin Description (continued) PIN FUNCTION SKIP Pulse-Skipping Control Input. This four-level input determines the mode of operation under normal steady-state conditions and dynamic output-voltage transitions: VDD (5V) = Forced-PWM operation Open (3.
PAGE 13
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers PIN NAME 14 LX1 Inductor Connection for SMPS1. Connect LX1 to the switched side of the inductor. LX1 serves as the lower supply rail for the DH1 high-side gate driver. 15 BST1 Bootstrap Capacitor Connection for SMPS1. The MAX17007/MAX17008 include an internal boost switch/diode connected between VDD and BST1. Connect to an external capacitor as shown in Figure 1. 16 GND Ground.
PAGE 14
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers +5V CVCC 1µF 16 R9 10Ω 4 VCC 18 VDD TON1 GND AGND ILIM1 ILIM2 CURRENT LIMIT VCC OPEN REF GND 60mV 45mV 30mV 15mV REF TON2 2 BST1 ILIM1 MAX17007 MAX17008 REF 3 DH1 LX1 ILIM2 (CCI) DL1 4-LEVEL SKIP PIN 5 11 25 CREF 2.2nF RREFIN1 = 80.6kΩ RREFIN2 = 121kΩ RREFIN3 = 249kΩ 1 RREFIN1 RREFIN3 8 SKIP PGND EN1 CSH1 EN2 CSL1 REF BST2 DH2 REFIN1 LX2 H = 1.0V L = 1.2V RREFIN2 DL2 6 CVDD 2.
PAGE 15
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers MAX17007/MAX17008 Table 1. Component Selection for Standard Applications VOUT1 = 1.0V/1.2V AT 12A (FIGURE 1) COMPONENT VOUT = 1.5V AT 12A (FIGURE 1) VIN = 7V to 20V TON1 = 220k (270kHz) VIN = 7V to 20V TON2 = 180k (330kHz) Input Capacitor (per Phase) (2x) 10µF, 25V Taiyo Yuden TMK432BJ106KM (2x) 10µF, 25V Taiyo Yuden TMK432BJ106KM Output Capacitor (2x) 330µF, 2.5V, 12m , C case SANYO 2R5TPE330MCC2 (2x) 330µF, 2.
PAGE 16
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers +5V CVCC 1µF 16 R9 10Ω 4 VCC 18 VDD TON1 GND AGND ILIM CURRENT CCCI PIN (pF) LIMIT VCC OPEN REF GND 60mV 45mV 30mV 15mV TON2 2 REF 120 180 220 470 MAX17007 MAX17008 CCCI 220pF ILIM2 FUNCTIONS AS V OUT CCI OUTPUT IN COMBINED MODE EN2 MUST BE GROUNDED CREF 2.2nF 5 25 1 RREFIN1 RREFIN3 DH1 LX1 3 11 RREFIN1 = 80.
PAGE 17
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers MAX17007/MAX17008 CURRENT BALANCE Gm Gm TON2 TON1 COMBINE (FB2 = VCC) SKIP COMBINE (FB2 = VCC) ILIM1 ILIM2 CSH1 CURRENT LIMIT 1 (FIGURE 8) CSL1 CURRENTSENSE GAIN CSH2 CURRENT LIMIT 2 (FIGURE 8) VALLEY CURRENT LIMIT VALLEY COMBINE CURRENT (FB2 = VCC) LIMIT CSL2 CURRENTSENSE GAIN Gm Gm BST1 BST2 DH1 DH2 LX1 LX2 VDD PWM CONTROLLER 1 (FIGURE 4) MUX PWM CONTROLLER 2 (FIGURE 4) VDD DL2 GND PGND FAULT1 CSL1
PAGE 18
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers +5V Bias Supply (VCC, VDD) The MAX17007/MAX17008 require an external 5V bias supply in addition to the battery. Typically, this 5V bias supply is the notebook’s 95%-efficient 5V system supply. Keeping the bias supply external to the IC improves efficiency and eliminates the cost associated with the 5V linear regulator that would otherwise be needed to supply the PWM circuit and gate drivers.
PAGE 19
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Free-Running Constant-On-Time PWM Controller with Input Feed-Forward The Quick-PWM control architecture is a pseudo-fixedfrequency, constant-on-time, current-mode regulator with voltage feed-forward. This architecture relies on the output filter capacitor’s ESR to act as a currentsense resistor, so the output ripple voltage provides the PWM ramp signal.
PAGE 20
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Switching Frequency The MAX17007/MAX17008 feature independent resistor-programmable switching frequencies for each SMPS, providing flexibility for applications where one SMPS operates at a lower switching frequency when connected to a high-voltage input rail while the other SMPS operates at a higher switching frequency when connected to a lower voltage rail as a second-stage regulator.
PAGE 21
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers V V tSTART1 = tSHDN1 = REFIN1 = REFIN1 1.3mV /µs SRSS1 tSTART2 = tSHDN2 = VFB2 VFB2 = 0.65mV /µs SRSS2 The soft-start circuitry does not use a variable current limit, so full output current is available immediately. The respective PGOOD becomes high impedance approximately 200µs after the target voltage has been reached.
PAGE 22
When SKIP is pulled to GND, the MAX17007/MAX17008 remain in pulse-skipping mode. Since the output is not able to sink current, the timing for negative dynamic output-voltage transitions depends on the load current and output capacitance. Letting the output voltage drift down is typically recommended in order to reduce the potential for audible noise since this eliminates the input current surge during negative output-voltage transitions. Figure 5 shows the pulse-skipping/discontinuous crossover point.
PAGE 23
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers In forced-PWM mode, the MAX17007/MAX17008 also implement a negative current limit to prevent excessive reverse inductor currents when VOUT is sinking current. The negative current-limit threshold is set to approximately 120% of the positive current limit. In combined mode, ILIM1 sets the per-phase current limit for both phases.
PAGE 24
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Output Voltage The MAX17007/MAX17008 feature preset and adjustable output voltages for both SMPSs, and dynamic output voltages for SMPS1. In combined mode, the output voltage is set by REFIN1, and all features for SMPS1 output-voltage configuration and dynamic voltage changes apply to the combined output. Figure 9 is the SMPS target decode block diagram.
PAGE 25
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Automatic Fault Blanking (SMPS1) When the MAX17007/MAX17008 detect that the internal target and REFIN1 are more than ±50mV (typ) apart, the controller automatically blanks PGOOD1, blanks the UVP protection, and sets the OVP threshold to max REF + 300mV.
PAGE 26
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Internal Integration An integrator amplifier forces the DC average of the FB voltage to equal the target voltage. This internal amplifier integrates the feedback voltage and provides a fine adjustment to the regulation voltage (Figure 4), allowing accurate DC output-voltage regulation regardless of the compensated feedback ripple voltage and internal slopecompensation variation.
PAGE 27
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers The undervoltage thresholds are -200mV for SMPS1 (fixed 1.05V and adjustable REFIN1), -200mV for SMPS2 in preset mode (fixed 1.5V output), and -100mV for SMPS2 in adjustable mode (0.7V feedback). A UV fault on one side does not affect the other side. Thermal-Fault Protection (TSHDN) The MAX17007/MAX17008 feature a thermal-fault protection circuit.
PAGE 28
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Quick-PWM Design Procedure Firmly establish the input voltage range and maximum load current before choosing a switching frequency and inductor operating point (ripple-current ratio).
PAGE 29
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers ILIMIT(LOW) > ILOAD(MAX) ⎛ LIR ⎞ ⎜1 − ⎟ ⎝ NPH 2 ⎠ where I LIMIT(LOW) equals the minimum current-limit threshold voltage divided by the output sense element (inductor DCR or sense resistor). The four-level ILIM setting sets a valley current limit of 15mV, 30mV, 45mV, or 60mV across the CSH_ to CSL_ differential input.
PAGE 30
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers INPUT (VIN) DH_ NH CIN INDUCTOR L RDCR RCS = LX_ MAX17007 DL_ MAX17008 NL DL R1 PGND R2 CEQ R2 = RDCR R1 + R2 COUT L RDCR = C EQ [ R11 + R21 ] CSH_ CSL_ b) LOSSLESS INDUCTOR SENSING FOR THERMAL COMPENSATION: R2 SHOULD CONSIST OF AN NTC RESISTOR IN SERIES WITH A STANDARD THIN-FILM RESISTOR. Figure 14.
PAGE 31
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers The easiest method for checking stability is to apply a very fast zero-to-max load transient and carefully observe the output voltage ripple envelope for overshoot and ringing. It can help to simultaneously monitor the inductor current with an AC current probe. Do not allow more than one cycle of ringing after the initial step-response under/overshoot.
PAGE 32
MAX17007/MAX17008 Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers Calculating the power dissipation in high-side MOSFET (NH) due to switching losses is difficult since it must allow for difficult quantifying factors that influence the turn-on and turn-off times. These factors include the internal gate resistance, gate charge, threshold voltage, source inductance, and PCB layout characteristics.
PAGE 33
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers ⎛ VOUT − VCHG VIN(MIN) = ⎜ ⎜ 1 − h × t OFF(MIN)fSW ⎝ ( ) ⎞ ⎟ ⎟ ⎠ where VCHG is the parasitic voltage drop in the charge path (see the On-Time One-Shot section), and tOFF(MIN) is from the Electrical Characteristics table. The absolute minimum input voltage is calculated with h = 1.
PAGE 34
3) Group the gate-drive components (BST capacitors, VDD bypass capacitor) together near the controller IC. 4) Make the DC-DC controller ground connections as shown in Figures 1 and 2.
PAGE 35
Dual and Combinable QPWM Graphics Core Controllers for Notebook Computers TRANSISTOR COUNT: 13,103 PROCESS: BiCMOS For the latest package outline information, go to www.maxim-ic.com/packages. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 28 TQFN T2844-1 21-0139 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.