_______________Detailed Description

VPP Switching

The MAX613/MAX614 allow simple switching of

PCMCIA card VPP to 0V, +5V, and +12V. On-chip

power MOSFETs connect AVPP and BVPP to either

GND, VCCIN, or VPPIN. The AVPP0 and AVPP1 control

logic inputs determine AVPP’s state. Likewise, BVPP0

and BVPP1 control BVPP. AVPP and BVPP can also be

programmed to be high impedance.

Each PCMCIA card slot has two VPP voltage inputs

labeled VPP1 and VPP2. Typically, VPP1 supplies the

flash chips that store the low-order byte of the 16-bit

words, and VPP2 supplies the chips that contain the

high-order byte. Programming the high-order bytes

separately from the low-order bytes may be necessary

to minimize +12V current consumption. A single 8-bit

flash chip typically requires at most 30mA of +12V VPP

current during erase or programming.

Thus, systems with less than 60mA current capability

from +12V cannot program two 8-bit flash chips simulta-

neously, and need separate controls for VPP1 and VPP2.

Figure 1 shows an example of a power-control circuit

using the MAX613 to control VPP1 and VPP2 separately.

Figure 1’s circuit uses a MAX662 charge-pump DC-DC

converter to convert +5V to +12V at 30mA output current

capability without an inductor. When higher VPP cur-

rent is required, the MAX734 can supply 120mA.

Use the MAX614 for single-slot applications that do

not require a separate VPP1 and VPP2. Figure 2

shows the MAX614 interfaced to the Vadem VG-465

single-slot controller.

To prevent VPP overshoot resulting from parasitic

inductance in the +12V supply, the VPPIN bypass

capacitor’s value must be at least 10 times greater than

the capacitance from AVPP or BVPP to GND; the AVPP

and BVPP bypass capacitors must be at least 0.01

µF.

______________________________________________________________Pin Description

Dual-Slot PCMCIA

Analog Power Controllers

4

_______________________________________________________________________________________

PIN

MAX613

14

8

VPPIN

1

1

GND

Ground

2

2

AVPP1

Logic inputs that control the voltage on AVPP (see Table 1 in

Detailed Description).

3

3

AVPP0

4

—

BVPP1

Logic inputs that control the voltage on BVPP (see Table 2 in

Detailed Description).

5

—

BVPP0

6

—

VCC1

Logic input that controls the state of DRV3 and DRV5 (see Table 3 in

Detailed Description).

7

4

VCC0

Logic input that controls the state of DRV on the MAX614. On the MAX613, both VCC0 and

VCC1 control the state of DRV3 and DRV5 (see Table 3 in

Detailed Description).

—

5

DRV

Open-drain power MOSFET gate-driver output used to switch the slot VCC supply voltage.

DRV sinks current when VCC0 is high and goes high impedance when VCC0 is low.

8

—

DRV5

Open-drain power MOSFET gate-driver output used to switch the slot VCC supply voltage (see

Table 3 in

Detailed Description).

9

—

DRV3

Open-drain power MOSFET gate-driver output used to switch the slot VCC supply voltage (see

Table 3 in

Detailed Description).

10

—

–

S

—

H

—

D

—

N

Logic-level shutdown input. When

–

S

—

H

—

D

—

N is low, DRV3 and DRV5 sink current regardless of the state of

VCC0 and VCC1. When

–

S

—

H

—

D

—

N is high, DRV3 and DRV5 are controlled by VCC0 and VCC1.

11

—

BVPP

Switched output, controlled by BVPP1 and BVPP0, that outputs 0V, +5V, or +12V. BVPP can

also be programmed to go high impedance (see Table 2 in

Detailed Description).

12

6

AVPP

Switched output, controlled by AVPP1 and AVPP0, that outputs 0V, +5V, or +12V. AVPP can

also be programmed to go high impedance (see Table 1 in

Detailed Description).

13

7

VCCIN

+5V power input

+12V power input. VPPIN can have 0V or +5V applied as long as VCCIN > 2.85V.

MAX614

NAME

FUNCTION