MAX3370(2001) Ver la hoja de datos (PDF) - Maxim Integrated
Número de pieza
componentes Descripción
Fabricante
MAX3370 Datasheet PDF : 10 Pages
| |||
1µA, 2Mbps, Low-Voltage Level
Translators in SC70
PIN
MAX3370
MAX3371
1
1
2
2
3
3
4
4
5
6
—
5
Pin Description
NAME
FUNCTION
VL
GND
I/O VL
I/O VCC
VCC
SHDN
Logic Supply Voltage
Ground
Input/Output Referred to VL
Input/Output Referred to VCC
Power-Supply Voltage
Shutdown. A high turns on the device. A low shuts down the device. I/O VCC
and I/O VL are high impedance in shutdown.
Detailed Description
The MAX3370/MAX3371 provide the necessary level
translation to allow data transfer in a multivoltage sys-
tem. These devices transmit data between an I/O pin
referenced to VCC and an I/O pin referenced to VL. The
VCC supply voltage range is from +2.5V to +5.5V, and
the VL supply voltage range is between +1.6V and
+5.5V. The MAX3371 features a shutdown mode in
which I/O VCC and I/O VL are placed in a high-imped-
ance state and supply current drops to 1µA.
The MAX3370/MAX3371 are bidirectional level shifters
allowing data transfer from the VCC side to the VL side,
and from the VL side to the VCC side. Both devices
operate at speeds up to 2Mbps with an active driver
and up to 500kbps with an open-drain driver.
Level Translation
The MAX3370/MAX3371 provide bidirectional level
translation between I/O pins referred to VCC and VL.
I/O VCC and I/O VL are internally pulled up to their
respective power-supply rails through 10kΩ resistors.
VCC must be between +2.5V and +5.5V, and VL must
be between +1.6V and +5.5V. For proper operation, VL
can not exceed VCC.
The MAX3370/MAX3371 can operate at data rates up
to 2Mbps when driven by an active (push-pull) driver
with a 10pF load, 1Mbps when driven by an active dri-
ver with a 50pF load, or 500kbps when driven by an
open-drain driver with a 30pF load. The internal pullups
allow these devices to be driven by open-drain drivers.
MAX3371 Shutdown Mode
The MAX3371 enters a low-power shutdown mode
when SHDN is driven low. Connect SHDN to VL or drive
high for normal operation. Activating shutdown mode
disconnects the internal 10kΩ pullup resistors on I/O
Functional Diagram
VL
VCC
MAX3370
I/O VL
S1
R1
MNSW
SPEEDUP
S2
R2
I/O VCC
GND
VCC and I/O VL. As a result, the supply current
decreases to <1µA, and the I/O lines are high imped-
ance. The high impedance I/O lines in shutdown allow
use in a multidrop network. When in shutdown, I/O VL
can be driven to VL and I/O VCC can be driven to VCC.
Speed-Up
The speed-up circuit is a one-shot generator that helps
the rise time of the output waveform in the low-to-high
transition. When triggered, switches S1 and S2 turn on
for 320ns to pull up I/O VL and I/O VCC. This greatly
reduces the rise time and propagation delay for the
low-to-high transition as well as improves the duty
cycle (closer to 50% for an ideal square-wave input).
See the scope plots in the Typical Operating
Characteristics for the speed-up circuitry in operation.
8 _______________________________________________________________________________________
Share Link: 