MAX1761EEE Maxim Integrated Products, MAX1761EEE Datasheet - Page 10

• Manufacturer Part Number: MAX1761EEE
• Description: DC/DC Switching Controllers
• Manufacturer: Maxim Integrated Products

Specifications of MAX1761EEE

• Number Of Outputs: 2
• Output Voltage: 2.5 V, 1 V to 5.5 V, 1.8 V
• Input Voltage: 4.5 V to 20 V
• Mounting Style: SMD/SMT
• Package / Case: QSOP-16
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Table 2. Component Suppliers
comparator has 40mV hysteresis to prevent startup
oscillations on slowly rising input voltages.
If VL is not driven externally, then V+ should be at least
5V to ensure proper operation. If V+ is running from a
5V (±10%) supply, V+ should be externally connected
to VL. Overdriving the VL regulator with an external 5V
supply also increases the MAX1761’s efficiency.
Small, Dual, High-Efficiency
Buck Controller for Notebooks
10
Table 1. Component Selection for Standard Applications
Fairchild
Semiconductor
Kemet
Panasonic
Rohm
Sanyo
Siliconix
Sumida
Taiyo Yuden
Input Range
Frequency
Complementary
P- and N-Channel
MOSFETs
Inductor
Input Capacitor
Output Capacitor
C urr ent- S ense
Feed b ack Resi stor s
SUPPLIER
COMPONENT
______________________________________________________________________________________
408-822-2181
408-986-0424
847-468-5624
760-929-2100
619-661-6835
408-988-8000
847-956-0666
408-573-4150
PHONE
5V to 18V
350kHz
Fairchild FDS8958A
7µH
Sumida CDRH104-
7R0NC
10µF, 25V
Taiyo Yuden
TMK432BJ106KM
330µF, 10V
Kemet
T510X 337K101
R
R
1
2
= Short
= Open
2.5V AT 2.0A
www.fairchildsemi.com
www.kemet.com
ww w.p anasonic. com
www.rohmelectronics.
com
www.secc.co.jp
www.vishay.com
www.sumida.com
www.t-yuden.com
WEB
5V to 18V
350kHz
Siliconix IRF7319
3.5µH
Sumida CDRH127-
3R5NC
2 x 10µF, 25V
Taiyo Yuden
TMK432BJ106KM
2 x 330µF, 10V
Kemet
T510X 337K010
R
R
1
2
= 1k
= 1k
2.5V AT 3.5A
The internal 2V reference is accurate to ±1% (max)
over temperature and can supply a 50µA load current.
Bypass REF to GND with a 0.1µF capacitor when REF
is unloaded. Use a 0.22µF capacitor when applying an
external load.
The Quick-PWM control architecture is a constant-on-
time, current-mode type with voltage feed-forward
(Figure 3). This architecture relies on the output ripple
voltage to provide the PWM ramp signal. Thus, the out-
put filter capacitor’s ESR acts as a feedback resistor.
The control algorithm is simple: the high-side switch on-
time is determined solely by a one-shot whose period is
inversely proportional to input voltage and directly pro-
portional to output voltage (see the On-Time One-Shot
section). Another one-shot sets a minimum off-time
(400ns typical). The on-time one-shot is triggered if the
error comparator is low, the low-side switch current is
below the current-limit threshold, and the minimum off-
time one-shot has timed out.
Free-Running Constant-On-Time PWM
5V to 18V
250kHz
Fairchild FDS8958A
10µF, 25V
Taiyo Yuden
TMK432BJ106KM
330µF, 10V
Kemet
T510X 337K010
R
R
7µH
Sumida CDRH104-
7R0NC
3
4
Controller with Input Feed-Forward
= Short
= Open
1.8V AT 2.0A
Voltage Reference (REF)
5V to 18V
350kHz
Fairchild FDS8958A
10µH
Sumida CDRH104-
100NC
10µF, 25V
Taiyo Yuden
TMK432BJ106KM
330µF, 10V
Kemet
T510X 337K010
R
R
1
2
= Short
= Open
3.3V AT 2A